Chapter 17

Property Rights: Natural or Conventional?

One distinctive feature of libertarianism is its position on property rights. In addition to the natural right to control and dispose of one’s own person and powers (which they construe as self-ownership), libertarians typically also hold that individuals have natural rights to property (Nozick 1974, Cohen 1995, Vallentyne and van der Vossen 2014, Narveson 2001). Natural property rights are prior to rule-governed legal or social practices of property and constrain those practices. Libertarians differ amongst themselves on the extensiveness of natural property rights: While left-libertarians hold that external resources may only be appropriated on an egalitarian basis, right-libertarians typically adopt a weaker construal of the constraints on appropriation, for example, Nozick’s view that, to be justified, appropriation must not worsen the situation of others.

Both these libertarian views differ from a contrasting account, more popular among contemporary philosophers. This standard view instead sees property as a conventional right conferred by legal institutions or social practices. Here, the right to property is held to depend on background social rules. Hume, for example, argues that property is determined by conventions that assign ownership of objects and define the conditions for valid contracts and transfers. These conventions develop because humans have needs that can only be met through social cooperation, and because the scarcity and instability of goods poses an obstacle to cooperative enterprises (Hume 1978: 484–513). For conventionalists, a moral duty to respect others’ property does not arise until a system of background practices is in place, and the conventions themselves are not to be explained by appeal to any natural moral principle (Mack 2010: 57).

Most left-liberals today take a conventionalist approach. Rawls, for instance, sees property rights as appropriately determined by just background institutions, including a competitive market set within a basic structure that guarantees (1) the fair value of political liberty, (2) fair equality of opportunity, and (3) the difference principle.¹ Property rights, for him, are nothing more than the legitimate expectations acquired by agents as they comply with the rules of such distributively just institutions (Rawls 1999: 268).

I am not a libertarian. But unlike other left-liberals, I see a grain of truth in the idea of natural property rights. I believe individuals can acquire some kinds of property outside a framework of social institutions, and that other people would have a natural duty to respect these acquisitions. However, my construal of natural property rights is much weaker that of libertarians, who typically conceive these as rights to property in the “full liberal sense.” Instead, I believe our natural property claims are limited, essentially consisting in secure rights of use and possession. Other aspects of liberal private ownership—like the right to alienate, to bequeath, to draw income, and to possess apart from use (incidents fundamental to the development of inequalities in modern societies)—are fully conventional, on my view. I do not believe that contemporary legal institutions are constrained by prior natural rights in defining and regulating these incidents. Thus, I take a hybrid view of property: While some limited forms of ownership obtain outside shared social institutions and constrain how these institutions should be designed, not all aspects of property are similarly preinstitutional. My purpose in this essay is to set out a case for the hybrid view against its competitors, especially the libertarian and pure conventionalist approaches. In doing so, I will draw on arguments from the modern natural-law tradition, where I find precedent for the hybrid view.

A couple of preliminary clarifications: first, I use the term natural right to refer to a right that could be recognized by persons existing in a “state of nature,” independently of any social or legal institutions. Natural rights are possessed by persons simply in virtue of their humanity and regardless of their spatial or historical location (Simmons 2001: 185, Beitz 2009: 49). The binding force of natural rights is moral, not legal or conventional.

Second, I take for granted the claim, widely accepted by lawyers, that property is a concept that admits of an enormous variety of forms. Following Honoré, it is a commonplace that property comprises a bundle of specific incidents, which may vary from case to case (Honoré 1987a: 161). Thus, people may hold property in a more restricted sense than that captured by “full liberal ownership.” Someone may have, say, rights to use and manage a thing without also having the right to alienate, destroy, or alter it. In this case, it is still correct to say that this person has a kind of (limited) property in the thing. This clarification will turn out to be important for expounding my hybrid view, since the forms of preinstitutional property I endorse fall short of ownership in the full liberal sense.

1WHY NATURAL PROPERTY RIGHTS?

Suppose we deny that there are any natural property rights, holding instead that all rights over material goods depend on conventions. Then I believe we are led to some repugnant conclusions. This is easiest to see with respect to legal conventionalism. This view, most clearly endorsed by Hobbes and Bentham, holds that all property depends on a background system of positive law (Hobbes 1996: 171; Bentham 1962: 309).2 Hobbes and Bentham argue that positive law is necessary to generate rules with sufficient publicity, determinacy, and probability of enforcement for property to exist. If we accept legal conventionalism, however, a problem arises: What are we to say about cases where people lack legal institutions? Consider the inhabitants of failed states or non-state groups; on the legal conventionalist approach, these people must lack valid property rights, since they are without the institutions of positive law that would ground them. If all rights to material goods are given a legal conventionalist analysis, then it would seem that stateless people are morally free to force each other off their land or to take away one another’s goods (van der Vossen 2013). Intuitively, though, these acts seem clearly wrong.

Adopting a more informal, Humean view—which holds that property rights depend on social, not legal, conventions—might enable us to avoid this repugnant conclusion. After all, it seems quite likely that a group of stateless people would develop some informal rules regarding their possession of material goods. But the informal conventionalist approach still faces a problem. Though it can explain why members of the relevant society might have a duty to respect one another’s property, it cannot explain why an outsider is bound to respect their practices. Think of Christopher Columbus sailing up to the island of Hispaniola in 1492; it certainly seems that he and his sailors wronged the inhabitants by forcing them off their land (at least absent any compelling justification of necessity). Yet the Humean approach cannot account for this wrong; since Columbus had never previously interacted with the Hispaniolans, the two groups lacked the shared conventions that might have generated a duty to respect property. (Recall that the hallmark of the informal conventionalist approach is the claim that duties to respect rights in material goods do not arise until a system of conventions comes to be generally recognized and respected within a given population).

Reflection on cases like these, I think, places the doctrine of natural property rights on its strongest footing. Unlike the conventionalist, the proponent of natural property rights can argue that the duty to respect others’ possession of material goods is a moral duty, the force of which does not depend on the prior existence of established background practices and which holds even in a “state of nature.” On a natural-rights view, the minimal elements of human morality encompass a duty to respect at least some claims to external goods.

How should we conceive natural property rights? Here I invoke a traditional method: the imagined transition from common ownership. This method—found in the work of Grotius, Pufendorf, Locke, and Kant—begins by postulating a primordial scenario in which goods are commonly held and asks why it would be justifiable to move away from that scenario to one in which people held exclusive rights in material things. There are important questions about how to interpret common ownership. Dating back to Samuel Pufendorf, it has been traditional to distinguish two ways of understanding this scenario. A negative common is unowned by anyone and equally open to all persons, each of whom has a liberty-right to use the world though no exclusive claim-right to anything. A positive common is one in which all persons jointly own the world, in the sense of holding some “undivided proportional share” in it (Simmons 1992: 238). The nature of this moral right to a proportional share is open to further specification, as (1) a liberty to use the undivided common, surrounded by a “protective perimeter” of claim-rights imposing duties on others to refrain from interfering with our permitted use (Hart 1982); (2) equal influence in decision-making about the undivided common; or (3) an equal share in the (to-be-divided) common, and so on.

Starting from the common ownership scenario might be thought to undermine the legitimacy of unilateral appropriation, however. As G. A. Cohen puts it, why is the original appropriation of goods “not a theft of what rightly should (have continued to be) held in common” (Cohen 1995: 73)? In a negative common, appropriation deprives others—without their agreement—of the option of using a particular good. In a positive common, appropriation might be thought to deprive co-owners of their undivided proportional share. Yet how can someone’s unilateral appropriation have this effect? Samuel Pufendorf powerfully presses this worry; he objects that taking is not the same as “acquiring, since the former is a mere physical act, whereas the latter involves a moral effect” (Pufendorf 1934, 4.6.7), and he holds that “assuming an original equal faculty of men over things, it is impossible to conceive how the mere corporal act of one person can prejudice the faculty of others, unless their consent is given, that is, unless a pact intervenes” (Pufendorf 1934, 4.4.5). Pufendorf’s worry is that by appropriating, the property holder seeks to act as a kind of legislator for others, imposing new obligations on them that they did not previously have (van der Vossen 2013: 66–67). How could a single individual have the authority to change others’ moral situation in this way?

Contra Pufendorf and following Grotius and Locke—at least on one, possibly heterodox, interpretation of the latter (Scanlon 1981; Tully 1980)—I argue that individuals can bring about limited moral rights to external things through unilateral appropriation and that they can do so compatibly with common ownership. Why should this be so? Recognizing some moral rights to external things, I believe, is instrumental to protecting other, more familiar, rights. Notice that on most accounts of justice, we have pre-existing natural duties to respect other people’s self-preservation and freedom. Every plausible moral theory holds that we are bound by a number of general duties that we have done nothing voluntarily to incur. Yet it is difficult to see how we could fulfill these duties without at least sometimes respecting others’ possession of material goods, when these are currently serving as essential supports for those same basic rights. Clearly it is necessary to appropriate some material goods (at the very least, food and drink, clothing, shelter, and the means of producing them) in order to guarantee self-preservation. Further, it also seems necessary to appropriate external things in order to exercise freedom. Nearly any complex plan or project we might wish to pursue requires material goods. Imagine, for example, that I want to paint a landscape. In order to carry out this project, I need to claim rights over the paint, brushes, and canvas sufficient to enable me to execute it without fear of someone else coming in and undoing what I have done (Stilz 2009: 42). If allowing certain exclusive uses of material goods by other people is instrumental to fulfilling our general background duties to respect their self-preservation and freedom, then, it seems we ought to be obliged not to interfere with at least these particular uses of external things. Moreover, these duties to respect exclusive use, I believe, are consistent with at least one interpretation of common ownership canvassed above: the “protected liberty” interpretation. On that interpretation, a positive common already implies a protected liberty to engage in permissible uses of it, which imposes a duty on others to respect our use.

Let me illustrate this idea by expounding the views of Hugo Grotius, whom I interpret as adopting a similar approach. Grotius holds that even prior to the invention of (full liberal) private property, we would have had weaker—yet still exclusive—rights over material resources. As Grotius puts it, “a certain form of ownership did exist” prior to the institution of private property, “but it was ownership in a universal and indefinite sense” (Grotius 2006: 317), which he further glosses as “the power to make use rightfully of common property” (Grotius 2006: 315). “[T]o have made use of Things that were then in common, and to have consumed them, as far as Nature required, had been the Right of the first Possessor: and if any one had attempted to hinder him from so doing, he had been guilty of a real Injury” (Grotius 2005, 1.2.1). Grotius’s limited natural right over material goods—which I call the primitive right—is a preinstitutional claim, not a human creation. It is a rightful power to make exclusive use of commonly owned things.

How extensive are Grotian primitive rights? Grotius says that this right gives us a claim to use and consume things “as far as Nature required.” Since each human being has a natural right to self-preservation, she also has the right to the necessary means for it. Some interpreters have read Grotius as limiting the primitive right to basic survival needs, but he speaks more expansively of it; some external goods, he says, “are necessary to being, while others are necessary only to well-being; or, one might say that they relate respectively to safety and comfort” (Grotius 2006: 23). He refers to many uses of things that are not directly tied to survival, for example, our right to use the sea to sail from place to place. Grotius does stress that there are limits to the primitive right, although these remain rather vaguely defined in his work: “there was an equality to be observed in that state, where all things were common, that one as well as another might have the liberty of using what was common” (Grotius 2005, 2.10.1.2). This expresses the idea—familiar from Locke—that to be justified, our appropriation must leave “enough, and as good” for others. No one should be prohibited, prevented, or excluded from using the common as a necessary material support to secure her own moral claims. That is, a justified appropriation must comply with a fair-share constraint in order to be respectful of others.

Does the primitive right impose correlative duties? Grotius suggests so: “no Man could justly take from another, what he had thus first taken to himself” (Grotius 2005, 2.2.2). As long as it is consistent with the fair-share constraint, our use of a thing places others under a moral duty to respect that use. Grotius illustrates this with a famous analogy from Cicero: “though the theater is common for anybody that comes, yet the place that everyone sits in is properly his own” (Grotius 2005, 2.2.2). The theater remains common, but each theatergoer has a right against the others to his seat for as long as he is using it. Like the theater, the world in “early times” is common, according to Grotius, but anyone who has laid hold of a particular good may properly claim it as his for the period of his own use. This holds at least so long as he dispossesses no one and respects the fair-share constraint.

Is the primitive right reducible to a simple duty to respect someone else’s body? Kant argues, in this vein, that some material objects fall within the compass of our duty not to assault others, when they are physically attached to those objects. He calls this a title to “empirical possession.” But Grotian primitive rights seem more extensive than this, as the analogy to the theater suggests. In the theater, you may get up to get a drink or void your bladder and return to your seat without losing your claim—your “use” does not cease as soon as you are no longer physically attached to the space. That seems appropriate, for otherwise our claims to external things would be too limited to guarantee self-preservation and freedom. Consider shelter; under an “empirical possession” system, one could claim only as much space as one’s body currently physically occupied. Others could come and share other bits of your cave, say, so long as they could do so without touching you. Were our claims to material things as minimal as this—constrained to what we could physically touch or hold, for the time we were holding it—it is unlikely we could secure our essential moral rights in a preinstitutional scenario.

I find Grotius’s primitive right plausible. The basic argument, as I see it, is that even absent the social institution of (full liberal) private property or an act of collective consent, we can acquire limited moral rights over material goods when those goods serve as essential supports for our other natural rights by playing an integral role in our self-preservation and projects—so long as we confine our use within reciprocally justifiable limits (see also Simmons 1992: 273–5). Suppose I come across a plot of land where you have built a hut, are tending a small garden, and have built various art projects. Does the fact that these goods are necessary to your sustenance and plans give me reason to refrain from interfering with them? I believe so. The fact that a material good is an essential support for someone else’s preservation and projects, I think, grounds a pro tanto moral duty on me to respect her use of it, even if I did not consent to her possession. If I have (or can procure) a place to live and food to eat somewhere else, then I ought to leave your hut, garden, and art projects alone. On the other hand, the strength of these pro tanto duties depends greatly on the background situation. If I am starving or lack any space in which to pursue my own projects, then I may be justified in interfering with “your” goods in order to obtain sufficient resources for myself. In this situation, interference is not a failure to respect your personality but a justified attempt to appropriate the resources necessary for my own.

How does Grotius’s primitive right fare against the objections from Cohen and Pufendorf canvassed above? I think it can survive these objections. Notice that on the Grotian account, it is not the appropriator who legislates the duty to respect others’ possession of material goods; instead—so long as possession helps secure background moral rights—pre-existing moral principles legislate that duty. Of course, by taking up a particular good, the appropriator does trigger these background moral duties, but this is unproblematic. We trigger particular “applications” of others’ moral duties all the time: when I cross the street, I trigger a requirement that drivers slow down to stop, thus “applying” their general duty not to unjustly threaten my life; when I post a flyer on a common message board, I trigger a duty on others not to post their flyers on top of mine, thus “applying” their general duty to respect my legitimate projects; and so on (Estlund 2008: 143; for a careful discussion of these issues, see van der Vossen 2013). Likewise, by taking up and using part of the world, an appropriator activates a particular application of others’ background duties of justice, namely the duty to respect his self-preservation and freedom. But he does not claim any moral power to create sui generis duties for other people that they wouldn’t already have had. This allows us to circumvent Pufendorf’s authority worry.

Nor should we think, with Cohen, that the appropriator commits a kind of theft. For the appropriator to commit theft, we would have to conceive the initial common ownership scenario in such a way that all exclusive use of goods without others’ consent was ruled out. But that would leave people unable to secure their most basic rights. So we should not conceive the initial common ownership scenario that way. Everyday examples support this: At a family-style meal—where all the food is the common possession of all the guests—we do not ask the consent of the other guests before serving ourselves a portion, so long as we leave enough for others to eat; at the movie theater, we do not ask the consent of all moviegoers before sitting down, so long as there are enough seats. Instead, so long as an appropriator respects reciprocally justifiable limits on appropriation, he simply particularizes the common in a way that is already morally permissible (Tully 1980: 3). In the primordial scenario, the division of the common may not yet have historically occurred, but nothing in the morality of the situation prohibits its occurrence.

2HOW EXTENSIVE IS THE PRIMITIVE RIGHT?

Thus far, I expect my argument to be relatively congenial to libertarians. But now a new question arises: What is the relation between the rights it is permissible to claim in the state of nature and liberal private ownership? Are these full private-property rights?

Following Honoré, let me define full liberal ownership (which I use synonymously with the Roman law term dominium) as “the greatest possible interest in a thing which a mature legal system recognizes” (Honoré 1987: 62). Nozick glosses ownership, in this vein, as involving “a permanent bequeathable property right” (Nozick 1975: 178). I believe the interest acquired through appropriation in the state of nature would fall short of a full liberal ownership right. There are two relevant differences: first, primitive rights confer more limited claims to exclude; and second, primitive rights do not extend to contractual transfer.

Let me first consider exclusion. Full liberal ownership specifies criteria for acquiring permanent legal title to things regardless of the role those things play in the owner’s life, and it allows the title-holder to exclude others from the good at will (Scanlon 1981: 125). If you enjoy full liberal ownership of a theater seat, you may keep others out of it even when you are not sitting there and even if you don’t like seeing plays. You may simply be an investor who buys theater tickets to sell them at a profit. As Pufendorf puts it, “such is the force of dominion that we are able to dispose of things, which belong to us as our own, at our pleasure, and to keep all others from using them” (Pufendorf 1934, 4.4.2).

Yet primitive rights, as I interpret them, confer a claim to exclude others from objects only insofar as those objects serve as essential material supports for a person’s normal life activities. Recall our earlier example in which I come across a plot of land where you have built a hut, a small garden, and art projects. The purpose of that example was to suggest that I ought morally to recognize a duty not to trespass on your land, because you are clearly occupying it and it is essential to your life. The signs of your ongoing use of the area allow me to recognize its centrality to your plans and pursuits. Primitive rights, as I understand them, thus comprise (1) a claim not to be interfered with in our uses of commonly owned things, so long as we confine that use to a fair share; and (2) a claim to ongoing possession of those goods that can be brought under our physical control (for example, through enclosure) and that are essential for our temporally extended plans and projects. This gives individuals a right, for example, to exclude others from personal dwellings and the moveables kept therein.

Why shouldn’t natural property extend to exclusion apart from use, as full liberal ownership does? Consider a revised “state of nature” case: Suppose I come across a hut and plot of land where someone once lived but which has gone unused for some time. It is clear, however, that the would-be “owner” wishes me to refrain from “his” land, as is evident from the “No Trespassing!” signs. Is it self-evident that I am morally obliged to refrain from trespass—say, that I have a duty not to shelter in the hut for the night? I deny that it is. The “natural” duty not to trespass, as I interpret it, is based on a prior moral requirement to respect someone’s self-preservation and life projects, so long as these are compatible with the reciprocal claims of others. In this case, however, it is not clear how my use of the area would constitute an interference with anyone’s legitimate life activities. Of course, my use may contravene the would-be owner’s intentions, but natural morality does not require me to respect anyone’s intentions.

It is of interest here that even Locke stresses the ways in which property in the state of nature is limited by the requirement of ongoing use. He holds that individuals may not appropriate in order to waste goods or allow them to spoil, and he comments that most useful natural products are of “short duration” (Locke 1980, §46). For this reason, Locke concludes that an appropriator in the state of nature “had no right, farther than his use called for any of them, and they might serve to afford him conveniences of life” (Locke 1980, §37, see also §31). Locke also stresses that this requirement, in the state of nature, “did confine every man’s possession to a very moderate proportion” (Locke 1980, §36) such as not to “prejudice the rest of mankind.” As Scanlon notes, this use-requirement is essential to Locke’s case for natural property rights; limiting natural property to what can be included within the compass of a normal life helps to ensure that an appropriator does not “entrench” upon others (Scanlon 1981: 126). Full liberal ownership, however, removes this limit, conferring on people expansive rights over things they do not use.

Full liberal ownership also differs from the primitive right in a second way: It involves powers of transfer, including rights to alienate, loan, rent, bequeath, and to derive income, all of which enable the possibility of market exchange (Tully 1980: 88). Grotius sees alienability as essentially differentiating full property from primitive rights: “the law of nature gave indeed a right to use things; as for instance, to eat or keep them, which are natural acts, but not to alienate them. This power was introduced by the fact of men, and therefore it is by that we must judge of its extent” (Grotius 2005, 2.6.6).

Should our conception of natural property extend to transfer? Return to our “state of nature” case: Suppose that some years ago, I built a hut, a garden, and art projects on my plot of land, and then on my deathbed I said, “This all must go to Arthur” (see Scanlon 1981: 125, for a similar example). Yet as it turns out, Arthur already has a large and abundant farm of his own—indeed, more than he and his family can use—while Beatrice has nowhere to live. Are Beatrice and third parties now under a moral duty to recognize my bequest, ceding “my” land to Arthur in accordance with my wishes? I deny that they are. How could the natural moral requirement to respect the self-preservation and legitimate life projects of others license a duty to allow the dead to control the disposition of objects that are needed by the living?

One might object here that while bequest may be problematic, prepolitical morality can at least account for inter vivos transfers. Even in a state of nature, one might promise one’s goods to someone, and morality might require one to follow through on that promise. But the institution of contractual transfer differs significantly from the prepolitical morality of promise-keeping. Not all promises are legally enforceable contracts, and the rules of contract are quite distinct from the rules of promising (e.g., most contracts do not require specific performance, so long as one pays monetary damages). Most importantly, the institution of legal contract requires the participation of the community in securing and enforcing the agreement (Shiffrin 2000; 2007). Yet I doubt persons in a state of nature would have any parallel obligation to enforce other people’s promises. If by promising Bernard your apples in exchange for his oranges, you could place me and others under an obligation to risk our lives to guarantee your agreement, and you would wield an unacceptable amount of power over us. So in the state of nature, I conclude that if you and Bernard fail to keep your promises, you have no remedy apart from self-help. Securely enforceable contracts depend on legal institutions created by the state. Moreover, the state may permissibly attach conditions—including taxation—to its provision of this valuable service.

So I agree with libertarians that even in a state of nature and as a matter of minimal human morality, we would recognize a general interest in forms of property that allow us to meet our needs and to engage in important personal plans and projects. But I doubt that our recognition of this interest would extend to recognition of full liberal ownership. The key question is how far background morality can take us. In my view, it would be consistent with background morality for the state of nature to be organized around a weaker system of entitlements than full liberal ownership; for example, a system that limited our powers to exclude others from objects apart from use, that required a person’s possessions to revert to the community at her death, or that did not include an enforceable claim to inter vivos transfer. While some might protest that these weaker entitlements do not amount to property as that term is normally used, we should recall my guiding assumption—mentioned at the start—that property is a concept that admits of a wide variety of forms, some of which fall short of full liberal ownership. The fact that many societies have, in fact, declined to recognize the full panoply of liberal ownership rights—by allowing for public, cooperative, or social ownership of the means of production; the existence of common pool resources; or the progressive taxation of income or capital gains—should lead us to look skeptically upon the thesis that natural morality self-evidently requires liberal private property (Honoré 1987b: 218–220).

Libertarians might object here that these more extensive liberal ownership rights are morally justified, because any system that does not include such rights will be less productive and efficient. After all, we are not able to find everything we need for ourselves, so rights of transfer are required to adjust possessions to individuals’ needs and interests. A conception of natural property that limits our power to transfer seems to rule out Pareto-optimal exchanges that would make everyone better off. Further, a society that allowed for permanent, exclusive, transmissible property could increase productivity, favor innovation, and boost the social product. The economic output of modern market societies, which depends on these more extended rights, dwarfs that of the premodern world (Brennan 2014: 107). So how could anyone object to including these additional claims?

I grant that market exchange is a beneficial social practice that societies often have reason to institute (though, as I will argue in a moment, the more extensive rights that enable exchange should be regulated). But I doubt that this shows full liberal ownership to be a natural right. Again, the key question is how far prepolitical morality can get us. Not everything that makes life richer, more commodious, or more productive is a natural right. Natural rights, as I understand them, are claims that could be recognized by any competent moral agent in a preinstitutional state of nature. Many beneficial practices do not count as natural rights in this sense. Analogously, I think there is a good moral case in favor of guaranteed elementary education in modern societies. But I deny there is a natural right to elementary education, since the applicability of this right depends on institutional preconditions—such a modern labor market and the infrastructure to provide public goods—that do not always obtain. So even if recognizing full liberal ownership enhances productivity and efficiency in many societies today, if full liberal ownership has significant institutional preconditions—as I have held it does—this line of argument would show only that it is a morally justified conventional right, not a natural one.

Indeed, both Grotius and Locke, on my reading, interpret full liberal ownership, in this vein, as a morally justified conventional right. Grotius suggests that the primitive right might have been sufficient, “had men persisted in their primitive Simplicity, or lived together in perfect Friendship” (Grotius 2005, 2.2.2.1). But instead, humans began to want “to live in a more commodious and agreeable manner,” which led them to institute a division of labor (Grotius 2005, 2.2.2.3). Once a division of labor was in place, common use became impossible, “first by Reason of the Distance of Places where each was settled, and afterwards because of the Defect of Equity and Love, whereby a just Equality would not have been observed, either in their Labor, or in the Consumption of their Fruits and Revenues” (Grotius 2005, 2.2.2.3).

While brief, Grotius’s view seems to go as follows: At some point, humans were no longer content to live on what each person could produce independently. So they decided to divide their labor and to specialize economically, which facilitates the creation of a social surplus. A division of labor, however, requires some system of exchange, and to work well, exchange requires people to have more extensive rights to goods than the primitive right allows. If people are entitled to benefit from a good only while they are actually using it, they have no incentive to produce anything beyond what they can personally use. Otherwise, their neighbors would simply “free ride” on their efforts, consuming the extra value they have created, and the laborer would receive no benefit from his pains. Incentives for greater productivity thus tell in favor of instituting more robust and more permanent rights over material things, that is, the kind of rights characteristic of full liberal ownership. Otherwise, the cooperative benefit of a more extensive social surplus could not be sustained.

Grotius stresses, however, that while there is reason to introduce these more extended rights, the binding force of full liberal ownership derives from a human agreement (Grotius 2005, 2.2.2.5):

Thus also we see what was the original of property, which … resulted from a certain compact and agreement, either expressly, as by a division; or else tacitly, as by a seizure. For as soon as living in common was no longer approved of, all Men were supposed, and ought to be supposed to have consented, that each should appropriate to himself, by right of first possession, what could not have been divided.

(Grotius 2005, 2.2.2.5)

In Grotius’s account, full liberal ownership is introduced in a collective choice to create new institutions necessary for more commodious living. Once full liberal ownership is introduced, as James Tully puts it, “there is a new definition of what is one’s own, and one’s rights over it” (Tully 1980: 83).

Like Grotius, Locke too highlights a shift away from natural property that occurs with the advent of an exchange economy. Unlike primitive natural rights, for Locke, modern private-property rights are determined by two conventions. The first is the agreement to the use of money: “the invention of money, and the tacit agreement of men to put a value on it, introduced (by consent) larger possessions, and a right to them” (Locke 1980, §36). Once money arises, land becomes scarce and it becomes necessary to form political societies and “by compact and agreement…[to settle] the property which labor and industry began” (Locke 1980, §45). The positive property laws instituted by governments, and the additional layer of treaties made between those governments, form the second conventional basis for property: “in governments, the laws regulate the right of property, and the possession of land is determined by positive constitutions” (Locke 1980, §50, see also §30 and Schlatter 1951: 158). Locke further notes that these more extensive conventional rights, once instituted, bring new inequalities: “different degrees of industry were apt to give men possessions in different proportions.” Market exchange gives people an incentive to “enlarge their possessions” beyond what they can easily include in their own life activities (Locke 1980, §48). This leads to “disproportionate and unequal possession of the earth” (Locke 1980, §50).

In response to these considerations, a libertarian might grant that full liberal ownership is a conventional right, because the establishment of permanent, transmissible titles has elaborate institutional preconditions. Still, he might reply that even if full liberal ownership would not obtain in a preinstitutional scenario, it is a right that ought to be universally recognized, because it is part of the ideally best institutional definition of property. This line of argument concedes that full liberal ownership depends on a relatively complex system of rules and regulations—like a formal system of title, valid definitions for wills and contracts, and legal remedies for breach—that would not obtain in a “state of nature.” Yet perhaps moral reflection can show that the institution of full liberal ownership can and should be established by all modern societies. All humans here-and-now should have strong private-property rights.

Does moral reflection tell in favor of the institution of liberal private property? To decide the question, one must compare libertarians’ favored strong definitions of ownership—including absolute rights to income and unfettered transfer—against possible alternative definitions of these rights. What needs to be shown is that everyone has reason to accept the rules that govern an exchange economy. Moreover, one must also define the social values in terms of which this hypothetical agreement should proceed. As libertarians stress, aggregate well-being is one relevant social value. But it is not the only one. If a property institution is to be justified, we must also expect that its operation “as a going concern” will not undermine any individual’s equal natural claims to freedom and self-preservation. Yet, as Locke highlights, liberal private property brings with it new inequalities that may threaten these natural claims.

I believe that if left unregulated, absolute property and contract rights will often undermine equal freedom by generating significant inequalities that become attached to social positions into which people are born. As Rawls stresses, the accumulated results of many separate market transactions may, over time, have the unintended consequence of undermining the preconditions for transactions among free and independent persons (Rawls 2005: 266–7). An important precondition for fair wage agreements, for example, is that they be made in a scenario where both parties have an acceptable degree of bargaining power. Yet absent regulation, firms may accumulate monopolistic or oligopolistic control of the labor market, imposing exploitative terms that their vulnerable employees lack a reasonable option to refuse. Similarly, one or a few wealthy families may come to control all a society’s land, enabling them to impose arbitrary conditions on others’ access to food or housing. Finally, unregulated bequest may, over time, bring about a class-stratified society, in which the privileged can purchase more advantageous educational opportunities for their children, providing them an overall better start in life. At the limit, one group may come to control nearly all of a society’s powerful and highly regarded positions, undermining fair opportunity, and may also wield unequal influence over its political decision-making mechanisms. This jeopardizes freedom for those from less favored backgrounds to shape their own lives.

This worry is not based on some “external” value—like equality of outcome—that goes beyond the moral considerations of self-preservation and freedom I have already appealed to. Instead, I believe the best justification for recognizing some “natural” rights to material goods also requires that the conventional right of full liberal property be regulated, over time, to ensure that everyone owns something and no one owns too much.

If full private-property rights are not compatible with equal freedom (or cannot be made compatible without ongoing regulation), then we ought not to recognize them (in the absence of that regulation). Like Rousseau, I believe that full private property is legitimate only when it is brought under the general will. Rights to exclude others apart from use and to transfer one’s property must be regulated—through taxation and state policies designed to ensure the wide dispersal of capital and wealth—so that the new inequalities they create do not undermine our other basic claims. As Rousseau puts it, a legitimate state must ensure that “all have something and none have too much of anything,” substituting “a moral and legitimate equality for whatever physical inequality nature may have placed between men” (Rousseau 1987, 1.9).

Of course, I expect that few libertarian readers will agree with me about this. Most will think that an ideally justified property institution would include much stronger definitions of ownership. Still, at any rate, this is the terrain on which the debate should proceed: What conventional rights of property do we all have reason to accept? To defend strong ownership, one must show that everyone can endorse an institution that includes these more robust claims on the basis of important social values—including not just efficiency and productivity, but also the equal claim to freedom and independence. One cannot argue for strong ownership rights by holding that they would have obviously obtained in some preinstitutional scenario and therefore stand as insuperable moral barriers against any state’s proposed redistributive policies.

While most left-liberals assume that a commitment to such redistributive policies depends upon pure conventionalism about property, I have argued that this is not the case. Absent a legitimate state or a social convention, primitive rights to possession and use could still arise along with natural duties among individuals to respect them. I believe we can grant this plausible thesis without undermining a theory that is significantly based on standards of distributive justice.

To sum up, then, I think we should eschew the libertarian view of property in favor of the hybrid view. The hybrid view grants that there are some natural property rights. But it sees these as limited to securing rights of possession and use in moderate proportions. In particular, these natural rights do not say anything about the terms on which people are entitled to exclude others from material goods when those goods do not directly support their own life activities. Natural property also leaves open the terms on which people might be entitled to contractually transfer their rights to others and, therefore, the rules that should govern a market economy.

3WHY NOT PURE CONVENTIONALISM?

While libertarians will surely find the hybrid theory’s conception of natural property too weak, those left-liberals who endorse pure conventionalism will press a different kind of objection. They will likely argue that the hybrid theory of property—while philosophically intriguing—is devoid of any practical interest. Surely the conditions under which primitive natural rights might be claimed are highly remote from our contemporary situation (Simmons 2001: 209). We do not live in a world in which there are large reserves of commonly owned goods waiting to be appropriated. Perhaps if someone in a primordial scenario made something central to her life activities, she would acquire a primitive right to it. But that truth is not germane to any practical problems that matter to us today. We live under well-established positive property conventions, and the problems we face have principally to do with how to structure or reform these conventions. What kinds of rules about contract, tort, corporate and inheritance law, fiscal and monetary policy, zoning, and environmental regulation should we recognize? How extensive should the protections for intellectual property be? Since different conventions will have different distributive consequences, these choices are consequential for social justice. Faced with the hybrid view, the conventionalist might simply reply: How does this theory matter for any property claims we might reasonably want to recognize today?

I believe that natural property rights do matter for some claims we may want to recognize today. One such claim is what I call the right to occupy geographical space. I believe that the moral foundation of a state’s territorial sovereignty rests, in part, on preinstitutional claims to occupancy held by its inhabitants. To see why, consider the following case:

Forced removal. Suppose a group of settlers gets together, overthrows the state of Chad, and drives out all the inhabitants, who become refugees in neighboring states. This group then sets up a perfect state on the territory. It rules legitimately, implements a fair distribution of property, and enjoys the unanimous consent of all its inhabitants.

(Stilz 2011)

We will still want to say that this perfect state does not have a right to its territory, at least not at its founding. This is because the settlers lacked any claim to construct a state there in the first place; they had no right to occupy the area.

An occupancy right, as I conceive it, comprises two main elements:

First, a liberty to reside permanently in a particular geographical space and to make use of that space for social, cultural, and economic practices. This extends to the liberty to travel freely through the area in order to access the places in civil society where those practices occur.

Second, a claim-right against others not to remove one from that area, to allow one to return to it, and not to interfere with one’s use of the space in ways that undermine the shared social practices in which one is engaged.

While less robust than a private ownership right, the right to occupy geographical space does have some “property-like” qualities: It confers the incidents of secure access, use, and possession. Yet occupancy is quite distinct from liberal private ownership. Occupancy rights are not exclusive; many people can share occupancy of the same area, and occupancy does not confer rights to alienate, to derive income, and so on.

I believe that the Grotian theory of primitive rights remains useful for theorizing occupancy, and—further—that we must suppose that individuals have natural occupancy rights if we are to understand the foundations of state territorial claims and, particularly, why actions like removal, exile, and settler colonialism are wrong. Pure conventionalists, however, face problems in theorizing these issues. They tend to begin from the assumption that the world is stably divided into territorially bounded societies, each of which has a system of positive property laws or conventions that determine the property rights of its members. This assumption is fine for some practical purposes, including the questions about corporate and inheritance law, zoning, and environmental regulation mentioned above. But it does not help us with another important issue: What makes the division of the globe itself legitimate? How might a particular group of people, and the state that represents them, come to have a claim to a particular area? And what if the legal institution that now legislates property rules in an area came to exist wrongly, through the dispossession of a prior state or group?

It is in answering these questions that I believe the primitive natural property rights postulated by the hybrid theory remains relevant today. Like Rousseau, I believe that sovereign states acquire their rights to land from the “right of the first occupant which it derives from individuals” (Rousseau 1987, 1. 9). Much along the lines sketched by the Grotius, I construe this occupancy right as a natural right to secure use and possession of geographical space. While I cannot fully elaborate or defend this view of occupancy here (though see Stilz 2013 and Stilz forthcoming), its relation to the hybrid theory of property should be clear enough. If I am correct, then the modern natural-law tradition—and the hybrid view of property rights it has bequeathed to us—remains important for understanding contemporary problems. Indeed, we cannot understand the moral foundations of territorial sovereignty without it.