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Property law is remarkably stable over time. Innovations in the form and content of ownership, for instance, are few and slow to catch on.[1] But that is not to say that property law, through its long history, has produced a clear and unequivocal understanding of what these fundamental concepts are. The idea of ownership around which the law of property is organized is itself a subject of controversy.[2]

Adverse possession is one aspect of property law that is caught in this controversy over the nature of ownership. Our idea of ownership influences how we answer basic questions about what it takes to succeed as an adverse possessor as well as more complicated questions about the morality of adverse possession. Seen one way, the law of adverse possession produces a radical transformation in the position of squatters pre– and post–limitation period, in some cases turning land thieves into owners. This approach, which I associate with the majority of American jurisdictions, sees adverse possession as morally paradoxical and so invites restrictions on deliberate squatting.[3]

Seen another way, the law of adverse possession concerns not the acquisition of new ownership rights by the squatter, but rather the extinction of the original owner’s superior right to possess due to her own inaction.[4] The squatter, on this view, does not acquire a new kind of right but is successful by default. This approach, found in current English law, downplays the radical change in the squatter’s position pre– and post–limitation period, thus avoiding some of the appearance of a moral paradox. But at the same time, the English approach ignores important conceptual differences between owner and possessor, treating them both simply as holders of rights to possess of differing strengths.

There is a third approach to adverse possession that I will argue makes sense of the morality of adverse possession without weakening the concept of ownership at work in the law. A basic component of this third approach is still the law in some Canadian jurisdictions and until recently had currency in much of the common law world, including England and Australia.[5] This is the inconsistent use test, according to which a squatter succeeds in a claim for adverse possession only where she establishes, by acts of possession that are inconsistent with the owner’s intended uses of the land, that the original owner lacks effective authority over the land.[6] This standard presents a significant hurdle for most adverse possessors.

A conventional reading of the inconsistent use test reflects our moral intuition that deliberate squatters are land thieves, undeserving of reward.[7] On this reading, the inconsistent use test appears to respond to the same considerations that motivate the current consensus view in the United States. But, I will argue, it would be a mistake to construe the inconsistent use test as just a reflection of our distaste, on moral grounds, for acquisitive squatters. Rather, the inconsistent use test suggests a very different moral foundation for the law of adverse possession. On this approach, the morality of adverse possession is not a particularized morality, concerned with the relative deserts of the owner and squatter or the relative merits of the uses they have for the land. We are evaluating the wrong thing if we look to the nature of the use or the user to establish the morality of adverse possession. Rather, the morality of adverse possession is indirectly established through the role of adverse possession in allowing property law to serve its moral function.

A system of property puts an owner in charge of an object. Where no one has the authority to be in charge of an object, users may manage to avoid conflict in practice. But it is the potential for conflict that is avoided when one person (or group, in the case of communal property) has the supreme authority over an object of property.[8] An owner authoritatively coordinates uses of an object by setting the agenda for it.[9] A squatter’s inconsistent use exposes a vacancy in the property system—an object of property over which the original owner no longer has effective authority. The squatter justifiably succeeds insofar as he fills that vacancy.

This study of the law and morality of adverse possession suggests a new analogy for understanding the role of adverse possessor, not as a land thief nor as a deserving labourer, but rather as something akin to the leader of a bloodless coup d’état.[10] A successful adverse possessor assumes the mantle of ownership for much the same reason that a successful coup d’état produces a government whose authority to rule is undiminished by the initial illegality of its path to power. The possibility of social order requires that someone wield ownership authority in the former case, and public authority in the latter. Adverse possession solves the moral problem of agendaless objects just as the recognition of the existing government (whatever its origins) solves the moral problem of stateless people.

The relationship between adverse possession and the legitimacy of post-revolution government is mostly one of analogy. But it is also more than this. Ownership, I will argue, is also a part of the larger system of public authority. It is part of the way that the state orders society. Of all the ways that the state relies on owners, the most important is the owner’s function of setting the agenda for an object and so setting a framework that organizes the uses others can make of it.[11] Insofar as the social order is in part constituted by owners, the state needs to ensure that owners are doing what the state promises they will do (or else face a breakdown in the social order). The adverse possessor, having asserted effective authority over the object and displaced the original owner, assumes an indispensable role in the property system and also the larger system of public authority of which the property system is a part.

This paper proceeds in two parts. In Part I, I will provide an overview of the three models of adverse possession. In Part II, I will develop the analogy between adverse possession and a successful coup d’état in order to explain the morality of adverse possession.

I. Three Models of Adverse Possession

The common law has produced a rich and complex debate about the law of adverse possession and the concepts of possession and ownership on which it is based. I will begin by examining in more detail the models of adverse possession that dominate this debate and the strikingly different conceptions of ownership and possession on which they rely.

A. A Proceduralist Approach

The first model, recently adopted in England,[12] emphasizes the non-adversarial and procedural nature of adverse possession. On this view, the adverse possessor succeeds where she possesses and intends to possess the land (in the ordinary sense) for the requisite time period. The dispossession of the true owner is simply the result of sufficient acts of possession by the adverse possessor rather than any intentional ouster of the true owner. Possession by the squatter logically entails dispossession by the owner because possession, by its very nature, is exclusive and single.[13] Nothing more is needed: no intent to own, and no “hostility” or conflict with the owner.[14] As a result, an owner can inadvertently lose title to her land even in circumstances where she has not abandoned or forgotten about it.[15] The original owner loses her right to regain possession simply by failing to act on her right in a timely fashion. When the original owner’s right to re-enter is extinguished, the squatter by default is left with a right to possess the land that is better than anyone else’s.[16] Adverse possession, on this model, is procedural rather than substantive because it sets out the process by which the owner’s rights are extinguished to the benefit of the possessor but does not carve out new rights for the possessor.[17]

The introduction of this model of adverse possession in England was a response to an older model of adverse possession based on a version of the inconsistent use test.[18] An English Court of Appeal decision from 1879, Leigh v. Jack,[19] set out the basic principle that if an owner has not abandoned or forgotten entirely about the land, the adverse possessor will succeed only by ousting him through inconsistent use.[20] A century later, there were rumblings that perhaps English courts, following Leigh, had gotten the law wrong.[21] In 1833, the English had reformed their statute of limitations.[22] The 1833 statute, on which the modern English, Ontario, and other Canadian statutes are based, stipulated that time starts to run against an owner from the moment that he discontinued possession or was dispossessed.[23] One interpretation of this statute that has become the current English view is that it did away with the requirement of “adversity” or ouster.[24] In 1977, Justice Slade in Powell delivered a strong critique of Leigh’s requirement of inconsistent use on the basis that it misconstrued the concept of possession.[25] The gist of his view was that an owner is dispossessed where the squatter is able to show that she and she alone is in possession, in the ordinary sense of the word.[26] An owner’s future plans, which may or may not materialize, do not count as continued acts of possession in the ordinary sense. Justice Slade also thought that the line of cases following Leigh wrongly understood animus possidendi to mean the intent to oust the true owner: a squatter cannot form the intent to oust the owner because she does not have the authority in law to do so. It would be impossible to require the squatter to intend to do what she is not in a position to do.[27] Thus, the intent to possess, on Justice Slade’s view, can mean only the intent to exclude others insofar as it is reasonably practicable and permitted by law.

Justice Slade’s decision in Powell, it has turned out, was an early sign of discomfort in England with what the inconsistent use test implies about the concept of ownership and its vulnerability. In 2004, the House of Lords in Pye overturned Leigh and applauded Justice Slade’s decision in Powell.[28] The House of Lords affirmed that any talk of ouster misconstrues what the law actually requires following the 1833 reforms, finding that ouster “is derived from the old law of adverse possession [pre-1833] and has overtones of confrontational, knowing removal of the true owner from possession.”[29]

On the current English model, the squatter does not engineer a takeover of the owner’s position and does not acquire a new ownership right at the end of the day.[30] This model of adverse possession rests on a particular understanding of ownership and its place in the common law. It fits with the old (feudal) view that the English common law does not have a concept of ultimate ownership of land.[31] Instead of ownership, on this view, there is just a hierarchy of rights to possess that are, relative to one another, either stronger or weaker.[32] To own is just to wield a right to possess that is good against all others.[33] A squatter who takes possession of land has a right to possess that is good against all others except someone with a prior and better right, such as the true owner and those claiming through him. Even though the squatter is a trespasser, the law will protect him from dispossession by anyone other than the true owner.[34] What is more, third parties cannot challenge his right on the grounds that someone other than he is the true owner.[35] Relative to the owner, the squatter’s right to possess is weak and defeasible until the limitation period runs. But relative to third parties, the squatter has a right to possess that is no different from that of the owner. When the owner’s right to regain possession is extinguished with the passage of time, the squatter simply enjoys a more robust protection of his own right to possess: he no longer faces the threat of re-entry by the owner.

A significant conceptual shortcoming of this approach is that it relies on an unsatisfactorily weak conception of ownership. The emphasis on relativity of title to explain the owner’s position suggests a parity between the position of the adverse possessor (as holder of a right to possess good against the whole world except someone with a superior right to possess) and the position of the owner (as holder of a right to possess that is good against the whole world including the possessor).[36] Of course, this model does, in a limited sense, distinguish between owner and possessor. For one thing, the model picks up on differences in the mode of acquisition. Thus, the adverse possessor has an original right to possess, acquired through the fact of possession, whereas the owner, in the usual case, has derivative title acquired through transfer or inheritance. This model also picks up on differences in the vulnerability of the owner’s and the squatter’s respective rights. The owner’s right to possess is good against all comers whereas the squatter’s right has more limited exigibility, good against all but the true owner. But the model fails to acknowledge the essential differences in the nature of the owner’s and the squatter’s rights, in keeping with the view that English law, unlike civilian law, gets by without the idea of ownership.

The perception that our system of property works without the concept of ownership is the product of property law’s roots in feudalism. The feudal origins of English property law produced a system of estates in which the legal rights in land were always held of someone higher up the feudal chain and ultimately held of the Crown. As Professor J.W. Harris wrote, “[s]ince what is conveyed is always an estate in the land, it has been widely assumed that ‘ownership’ of land, as such, is not a conception internal to English land law.”[37] But it would be a mistake to conclude that Anglo-American law has not produced a robust concept of ownership, albeit one that we need to glean from a wide array of property rules and doctrines.[38] It is of course true that the idea of ownership in the common law is rarely defined or directly discussed in property jurisprudence.[39] But this on its own should not lead us to overlook the concept of ownership within our legal system. We have, for instance, no evidence that Roman law, touted as the source of the civil law idea of dominium or complete ownership, contained any explicit articulation of the idea of ownership.[40] As one scholar of Roman law put it, “[i]t is well known that no ancient legal text contains a Roman definition of ownership.”[41] As I discuss elsewhere, the concept of ownership in Anglo-American property law emerges from the way in which various property doctrines, taken together, establish and preserve the special position of the owner as the agenda-setting authority.[42] Harris similarly locates the concept of ownership in the common law, arguing that ownership is quite simply an incident of legal estates in land.[43] As earlier property writers like H.W. Challis wrote, “[a fee simple] confers, and since the beginning of legal history it always has conferred, the lawful right to exercise over, upon, and in respect to, the land, every act of ownership which can enter into the imagination ... and, for all practical purposes [the right] of ownership.”[44] Of course feudalism complicates the idea of ownership that we find in English law,[45] but even in that context, the law understood and protected ownership. This is what Professor Baker meant when he wrote, “by the thirteenth century the tenant was in reality the owner of the land.” [46] The Crown by that point had created the safeguards that enabled tenants to exercise agenda-setting authority with respect to the land without interference by their overlords.[47]

The weakness of the current English approach to adverse possession is that it overlooks the existence of a robust conception of ownership in the common law; it suggests in its place a difference more of degree than of kind between the position of owner and possessor. This apparent symmetry between the positions of the possessor and owner, on this model, accounts for why the squatter need not aim to take over from the owner or intend to acquire a position other than the one she occupies already. A right to possess is all the possessor has to start with and all that she or anyone can have at the end of the day.

As we have seen, the recent English approach to adverse possession sidesteps the moral paradox by emphasizing the relativity of title. There is, on this view, no usurpation—no “private taking”—but simply the natural defeasibility of the owner’s right to possess where he fails to take action, thus leaving the adverse possessor’s right to possess that much stronger.[48] On the English view, as we saw above, we do not have a thief one minute and an owner the next, but rather someone whom the law recognizes as having a right to possess before the statutory period expires, and an even stronger right to possess thereafter. With respect to the owner himself, the squatter maintains a right to possess until the owner extinguishes it by re-entry.[49] And vis-à-vis the rest of the world, the law not only treats the squatter as having a right to possess but forbids mention of the better right of the true owner in a dispute with a third party.[50] Thus, although the adverse possessor is clearly a trespasser in English law before the statutory period expires, he occupies a position in law that is not at such a distance conceptually from the owner’s own. By emphasizing the relativity of title, the English do not treat the squatter as wholly damned as a wrongdoer one minute and wholly embraced by the law the next. However, the English view avoids the moral paradox in the law of adverse possession only by weakening the concept of ownership and setting up the fiction that the adverse possessor does not take over the owner’s position, but simply continues on in his own.

B. A Legal Moralist Approach

American approaches to adverse possession reveal a much greater concern with the effect of adverse possession in transforming squatters into owners.[51] Adverse possession in American case law and commentary is commonly described as a form of private “taking” or land theft, with the apparently anomalous result that the law through adverse possession sanctions theft.[52] This perceived shift in the law’s attitude to the squatter pre– and post–limitation period has led American courts and commentators increasingly to view the law of adverse possession primarily as a tool to correct the mistakes of good faith squatters:[53] deliberate squatters are, on this view, morally undeserving of the disproportionate reward that adverse possession is seen to deliver.[54] This has had an impact on the way in which the law of adverse possession has evolved in the United States. Few jurisdictions require that squatters deliberately challenge the title of the original owner in order to succeed, and some have gone so far as to limit the availability of adverse possession to good faith squatters.[55]

Historically, this was not the case. American approaches to adverse possession—and property generally—were and remain strongly responsive to utilitarian concerns. There was a time, particularly when the West was being settled, when it was seen as socially beneficial to encourage land-hungry locals to take over from absentee paper title holders.[56] As a result, many U.S. jurisdictions historically either did not inquire into the mental state of the squatter or even required that squatters have a hostile intent in order to prevail.[57] Over time, as unsettled land became increasingly scarce, deliberate squatting came to be seen in a different light, namely, as an attack on the security of ownership and as morally reprehensible.[58] The deliberate squatter came to be cast in the judicial imagination as a land thief to whom protection is offered only reluctantly, with a utilitarian’s eye to the larger ills avoided by doing so.[59] On this view, the apparent windfall enjoyed by a deliberate squatter who is transformed into the owner at the end of the day is justified, if at all, on the basis that adverse possession (1) prompts lazy owners to use their land or sell it off; (2) roots out stale claims while the evidence is still fresh so that title searches are simpler and less costly; and (3) respects the expectations of third parties who have relied on appearances.[60]

American instrumentalism held the moral paradox of adverse possession at bay for some time. So long as adverse possession performed an important service (e.g., rooting out stale claims, third party reliance, or the improved efficiency of land use), we suffered the moral incoherence of adverse possession.[61] Recently, however, American commentators have suggested that many of the supposed benefits of adverse possession are either not sufficiently valuable to offset the costs of rewarding theft, or better achieved through other legal mechanisms.[62] For instance, as Professor Fennell has argued, the interests of third parties are adequately protected by tort action for detrimental reliance, and land registries and recording systems now preserve evidence of title and so ensure the marketability of title previously threatened by old claims.[63] Others point out that it is no longer self-evident that adverse possession leads to more efficient uses of land because our society no longer straightforwardly prefers development and active uses of land over conservation and passive uses.[64] Not being able to locate the benefits of adverse possession for deliberate squatters in utilitarian terms, American courts and commentators have become increasingly responsive to what they see as the moral paradox of adverse possession.[65] As a result, judicial practice increasingly favours inadvertent or good faith squatters even in jurisdictions where adverse intent is formally no bar to a successful claim based on adverse possession.[66]

C. An Inconsistent Use Model

There is a third approach to adverse possession that acknowledges this radical transformation of squatters into owners without collapsing into a moral paradox. Although this approach is not perfectly articulated in any jurisdiction, its crucial component—the inconsistent use test—was once found throughout the common law world and is still the law in Canada. It is, however, increasingly under attack and wrongly so, as I think this paper will show.[67] According to the inconsistent use test, adverse possession is successful only when the possessor has used the land in a manner inconsistent with the original owner’s agenda for it.[68] The inconsistent use test requires the squatter to show that she has in effect ousted and intended to oust the true owner.[69] A friendly or amicable relationship between the adverse possessor and the owner will tend to rule out adverse possession.[70] The inconsistent use test thus preserves a wide scope for the owner to pursue the ends of her choosing insofar as she is immune from all but the most direct and confrontational challenge to her authority (which in a way limits, rather than introduces, “overtones of confrontation”[71] into the law).[72] The effect of the inconsistent use test is that an owner is quite secure in her position even if her plans for the land do not include present uses of it, so long as the possessor does not make use of the land in a manner that is inconsistent with her plans for it. Possession is not adverse where it does not defeat the owner’s plans for the property.

The inconsistent use test construes adverse possession as a bid to oust the owner from his position of authority.[73] The squatter’s acts of possession are sufficient for this purpose, only when they are inconsistent with the owner’s intended use and so pose a true challenge to the owner’s position. This understanding of “possession” may be at odds with the current English view of the ordinary meaning of the word, but it has deep roots. There are some similarities between the kind of possession required to defeat ownership on the inconsistent use test, and the idea of possession found in Roman law. On the Roman law conception, possession means roughly to “[sit] in power” or to “hold in the manner of an owner.”[74] Thus, the Romans distinguished between detention, which is occupation without the intention to own, and possession.[75] Possession, on the Roman view, requires both acts of possession and intention, animus possidendi. If possession means to hold in the manner of owner, then it follows that animus possidendi means the intent to own for oneself.[76] This understanding of possession complicates the position of deliberate squatters. For a deliberate possessor to “sit in power” or to “hold in the manner of owner,” he must in effect set out to displace the existing owner. Perhaps to avoid encouraging intentional ouster, Roman law limited the availability of adverse possession to good faith squatters.[77] The inconsistent use test takes the same bold understanding of what it means to possess but omits the moral safeguards that we find in Roman law against ouster by “bad faith” squatters.[78] On the inconsistent use approach, adverse possession is not restricted to good faith squatters but, on the contrary, is most readily achieved by deliberate squatters who challenge the owner’s claim of authority. The inclusion of deliberate squatters in the law of adverse possession makes good sense, given what I will argue below is the special function of adverse possession in property law: ensuring that everything capable of being owned is in fact effectively owned by someone.[79]

The inconsistent use approach suggests that there is a distinction in kind (and not just in degree of exigibility) between a possessor and an owner. From the perspective of the “layman”,[80] the special status of owners seems so obvious that we should expect nothing less from the law than its recognition as such. The key to understanding the distinction between owner and mere squatter is to understand the role of possession in establishing and maintaining their respective rights. Ownership does not depend on physical possession.[81] A person can own without ever having taken possession of the land in a physical sense. Actual possession, by contrast, is the underlying material manifestation of the squatter’s right to possess.[82] This is not to say that ownership is a matter purely of formal right. The owner’s position also depends on a material manifestation. But the material fact on which ownership depends is not actual possession but rather the effective authority to control the agenda.[83] The importance of effective authority as the basis for ownership explains why in Keefer, the owner is secure against the possessor so long as her agenda for the land is unaffected by her rival’s acts of possession.[84]

Because the underlying material manifestation of ownership is not ordinary possession but rather effective authority, mere acts of possession by a squatter that are not otherwise inconsistent with the owner’s plans do not present a sufficient challenge to the owner’s position. In order to take over as owner, an adverse possessor must not only exclusively occupy the land but must also defeat the owner’s agenda, which may or may not itself involve a physical presence on the land.[85] Thus, on this approach, an adverse possessor ousts the owner from her position of authority not by “merely squatting” but by taking possession in the manner of an owner and establishing that the original owner lacks effective authority. What this approach requires of the adverse possessor is both the intent to own and acts of ownership.[86] The possessor, to meet the inconsistent use test, must aim to take over from the true owner and to step into her shoes. It is not enough for him simply to intend to carry on in his own shoes as possessor, as it is on the current English approach.[87]

The importance of effective authority to the owner’s position continues the analogy between ownership and sovereignty.[88] Just as a ruler’s position primarily rests on authority and not coercion, the owner’s position rests on authority and not the brute fact of possession.[89] Ownership does not normally require that an owner actively possess the land; what it means to take charge as owner is to exercise the authority to set the agenda for a resource.[90] Authority, however, must be effective or its very legitimacy will be undermined.[91] This is true of a sovereign but also of an owner. Ordinarily, an owner’s authority to set the agenda for her land will be effective even in the absence of physical acts of possession. Where others accept her as owner, they accept also that her plans for the future use of the land, as well as her present uses, deserve deference.[92]

But this is not to say that possession in the ordinary sense has no role to play in preserving ownership. The role of possession in preserving agenda-setting authority is analogous to the importance of coercion to preserving the state’s effective authority. Generally, the state exercises its power by making laws or rules that people have reason to obey. The state’s power is primarily a function of its authority and not of its coercive force.[93] But where people disobey the law and so challenge the state’s authority, the state will need to resort to coercion to bolster the effectiveness of its authority.[94] Similarly, where others disregard an owner’s authority by challenging his agenda through inconsistent use, an owner may have to resort to actual possession to remain in power with respect to his land.[95]

The inconsistent use test is typically applied in resolving a contest between a deliberate squatter and an owner-occupier. There has been some confusion in the case law about how to extend this approach in two other contexts: where the owner is an investor or speculator who does not make present use of the land, and where the adverse possessor acts in good faith. One complaint often levelled against the inconsistent use test is that investors with plans to develop land in the future are, vis-à-vis an adverse possessor, in a better position than an owner who is making present use of her land.[96] An investment-driven agenda, it is thought, is less likely to be threatened by a squatter’s present acts of possession because few present uses will be inconsistent with plans to sell or to develop the land in the future. The concern is that the inconsistent use test protects rather than discourages absentee ownership.[97] This would of course be problematic because absentee owners fail to discharge the most basic obligation of ownership: the duty to assume fully the position of owner.[98] But the inconsistent use test, properly understood, is not a mechanism for protecting absentee owners. There is, first of all, a distinction between a speculator and an investor with actual plans to develop property in the future. An owner with actual investment plans is subject to the discipline of the threat of adverse possession just as much as the owner who is presently using the land.[99] If I, for example, plan to erect a building on vacant land, my development plans require that the land remain vacant. An adverse possessor who occupies the land and, in particular, who erects a structure on it interferes with my plans to keep the land vacant until such a time as I begin construction. The developer is not relieved of the burden to occupy his position fully as owner on the inconsistent use test. It is just that what it means to occupy the position of owner is to maintain agenda-setting authority rather than to engage in an immediate, active use. A developer is forced to pay attention to her holdings and to exercise her authority with respect to them just as much as an owner-occupier is. But this obligation is fulfilled by establishing the agenda for the land, even if that entails postponing active use of it. A developer who has set an agenda for it—one that a squatter can indeed interfere with—is not an absentee owner. By contrast, the speculator who has no plans for the land herself, but rather holds on to it in anticipation of its value to others, is a kind of absentee owner. But the inconsistent use test need not be interpreted as providing greater protection to the speculator than to the investor-developer or owner-occupier. One approach found in the case law is to impute to the speculator, who has no intended use, the intention that no one use the land.[100] A better approach, which does not rely on a distortion of the facts, is simply to treat the speculator as having in effect discontinued possession by failing to exercise agenda-setting authority—a state of affairs that makes her formal title vulnerable to an adverse possessor who does exercise actual authority in her place.

Let me now turn to the problem of the good faith squatter. The good faith squatter honestly but mistakenly believes that he owns the property and so is unaware of the existence of a true owner. Some courts have found the inconsistent use test difficult to apply in these cases. The good faith squatter cannot form an intent to oust the owner and to assert authority in her stead if he is unaware of the owner’s existence. And in cases of mutual mistake, the good faith squatter cannot have been said to have acted inconsistently with the true owner’s agenda because the true owner would not, in that case, have been in a position to form one. The obstacles that the inconsistent use test presents for the good faith squatter are hard to explain if we see adverse possession through the lens of legal moralism, which demands that there be some connection between the reward of ownership through adverse possession and the individual desert of the squatter. As a result, jurisdictions that have adopted the inconsistent use test in the context of deliberate squatters have subjected good faith squatters to a much less rigorous test for adverse possession than deliberate squatters.[101]

There is, however, a way of extending the inconsistent use test in the context of the good faith squatter that neither disqualifies her in every case nor treats her good faith as a count in her favour. An approach based on inconsistent use need not be read as requiring that a squatter oust the owner in every case. The inconsistent use test simply resolves, as between two contenders, the question of who in fact has authority. The inadvertent squatter should be able to succeed in the limited circumstances where adverse possession can proceed without ouster because the true owner does not claim authority over the land but rather has discontinued possession.[102] This is one way to resolve cases of mutual mistake, where the true owner fails to claim agenda-setting authority because she is unaware that she is in fact the owner.[103] Where the owner has no intended use of the land because she does not know it is hers, she has, in a sense, vacated the position, leaving it open to the inadvertent squatter to assume the position in her place.[104] This analysis would apply equally in cases where the owner is unilaterally mistaken about her rights: by failing to exercise her authority, she has created a vacancy that may be exploited by either a knowing or inadvertent squatter.

Where, however, the owner has not discontinued use, a squatter must establish that he has ousted the owner and has effective authority. In cases of unilateral mistake, where a good faith squatter believes he is the owner but where the true owner continues to exercise effective authority over the land, the squatter has not taken over the position of owner. It is true enough that the good faith squatter in cases of unilateral mistake will find it next to impossible to satisfy the inconsistent use test. But this is problematic only if we think that there ought to be some connection between the virtue of the squatter and the reward of adverse possession. It is precisely this kind of legal moralism that I challenge in the discussion that follows, where I will argue that it is not on the merits of the use or the user that adverse possession is justified, but rather on the imperative in any property system to guard against vacancies in the position of owner.

The inconsistent use approach avoids the conceptual blandness of the English approach but risks being mired in the moral paradox to which the American approach is so sensitive. As we have seen, there is a current model in English law that distinguishes between owners and possessors not in kind, but in degree, primarily in terms of the exigibility of the right (exigible against all others in the case of the owner, and against all but those with a superior right to possess in the case of the possessor).[105] The inconsistent use test, by contrast, sets us up a much sharper distinction between owners and possessors. At the same time, it presents a startling shift in the law’s attitude toward the adverse possessor pre– and post–limitation period from a mere possessor (with no legal right to oust the owner) to owner with full protection.[106]

II. Revolution and Rehabilitation

On what grounds can we justify the transformation of squatters into owners? To understand the moral significance of adverse possession, we need to begin with the proper analogy. Much of the moral analysis of adverse possession has proceeded on the basis that adverse possessors are land thieves. I will begin here by explaining why it is inapt to think of adverse possessors as land thieves. Following that, I will present an analogy between adverse possession and revolution or, more precisely, a bloodless coup d’état, which better illuminates the nature of the adverse possessor’s claim and also what justifies the law’s recognition of it. The recognition of the adverse possessor’s (private) authority solves the moral problem created by an agendaless object, just as the recognition of the existing government’s (public) authority, whatever its origin, solves the moral problem of a stateless people. The morality of adverse possession, seen this way, does not turn on any particularized evaluation of the squatter’s deserts or her uses of the land. I am thus not proposing that adverse possession is justified in the same way that some argue a conscientious revolutionary is justified in resisting an oppressive or otherwise unjust sovereign.[107] Rather, the morality of adverse possession is found where we might least expect it, in its positivist strategy of ratifying the claims to authority of a squatter without regard to the substantive merits of her agenda or her personal virtue.

What distinguishes theft or robbery from adverse possession? Consider for a moment the characteristic modus operandi of the thief: the thief achieves his goals—permanent control of someone else’s property—either by force or by stealth.[108] The thief’s method tells us something about the character of his claim to the object. The thief takes physical possession of the object with intent to deprive the owner permanently of possession without making a counterclaim of authority. The thief does not enter into a contest for legitimate authority over the object, but rather, as the robber’s resort to force or the thief’s secrecy reveals, it is an assertion of control in spite of their recognition of the owner’s superior authority over the object. The thief aims to get away with wrongful possession in spite of someone else’s acknowledged authority. What is significant about this is that the thief is not inviting an evaluation of a competing claim to authority nor is he demanding to be judged the owner as a result of his actions. Insofar as the thief controls the object of property, his aim is to dupe society into thinking he is the owner, which is something quite different from trying to elicit a judgment that he is in fact the owner.

Contrast the character of the thief’s claims with the character of the adverse possessor’s claims. The adverse possessor demands public recognition of her authority as owner, which she achieves only where she manifestly has authority over the land in place of the original owner. Thus, adverse possession is successful only where it is peaceful, open, and notorious.[109] Stealth or force undermines the adverse possessor’s claims because by sneaking or forcibly removing the original owner, she in effect reveals that she herself lacks effective authority.

The character of an adverse possessor’s claim is much more like that of a new government following a coup d’état than that of a thief. An adverse possessor does not merely circumvent the authority of the original owner but rather displaces it by asserting his own claim to authority. The adverse possessor claims exclusive and supreme authority, as does a new government, whatever its origins. This explains the public nature of an adverse possessor’s authority. His claim amounts to a challenge to the owner’s position of authority through the assertion of his own authority, which is necessarily a public act. (By contrast, in a model in which the squatter is not cast as a challenger to the owner’s position, public claims of this sort are not a significant feature of adverse possession.)[110] The nature of an adverse possessor’s claim as a public assertion of authority also explains why an offer to purchase land or other written acknowledgments of the true owner’s status has the effect that the squatter’s possession, up until the acknowledgement or offer, is deemed to be possession on behalf of the owner.[111] The significance of such a written acknowledgement is not that it reveals the squatter’s awareness of the original owner’s claims and so his bad faith. Of course, a deliberate squatter knows that someone else has paper title to the land in question, just as the leader of a coup d’état knows that there is a government with a right to rule (perhaps because it was democratically elected). Rather, an acknowledgment or offer to purchase is significant because it amounts to acceptance of the true owner’s claims to legitimate authority inconsistent with the possessor’s own public assertions of authority (made notwithstanding the owner’s formal title).[112]

The analogy between adverse possession and a coup d’état helps to clarify the significance of the retroactive nature of the claim that the squatter makes. An adverse possessor and the leader of a coup d’état undergo a transformation once they succeed in displacing the existing authority. The adverse possessor becomes owner, and the leaders of a coup d’état become the new government. This transformation is retroactive: just as a new government’s legitimacy is immune from challenge on the ground that it came to power illegally, so too is an owner immune from challenge on the ground that she once was an adverse possessor.[113] We look back and retroactively construe the squatter as the owner from the outset just as we construe the leaders of the coup as the government from the moment they have acquired effective authority.[114] The difficulty in ascertaining the original owner’s and the former government’s loss of authority (but also the importance of so doing) explains why there is a time lag in the law’s validation of the squatter’s and the new government’s authority.[115] The squatter must establish that the owner lacks effective authority on day one but then must still wait out the time period set by the statutory period before the law recognizes that she has taken over from the original owner. This period is necessary to determine whether the original owner has in fact failed to exert effective authority from day one. The loss of authority cannot be, as Hart put it, “verified or falsified ... in short spaces of time.”[116] It is difficult to pin down precisely when de facto authority actually ceases to exist simply because authority survives some resistance or interruption.[117]

The retroactive nature of adverse possession confirms that ownership authority is conclusive and not provisional. The adverse possessor’s de facto authority does not compete with the owner’s de jure authority during the statutory period. Rather, as we confirm after the waiting period, there was all along but a single person whose decisions about the object are authoritative. The retroactive nature of adverse possession also explains why the successful squatter, like the leaders of a successful coup d’état, cannot be held to account for wrongdoing. The adverse possessor is recognized as owner from day one even though, had he not succeeded, he would have been liable for trespass, just as the leaders of a failed coup d’état would have been liable for treason.[118]

A. Justifying Adverse Possession

What justifies adverse possession on this approach? At first glance, the analogy of adverse possession to a coup d’état appears to raise as many moral worries as the analogy of adverse possession to land theft. The positivist’s answer—that the adverse possessor, like the new ruler, in fact wields authority—does not seem to provide an answer to why we ought to recognize the adverse possessor’s (or the new ruler’s) claims to authority. There are, however, good justificatory reasons for the attention that the law pays to facts on the ground in the case of adverse possession, just as there are good justificatory reasons for recognizing the new government’s post-revolution rule.

Let me start by explaining the positivist’s claim that a new government has legitimate authority in spite of the wrongfulness of its route to power and in spite of the existence of another organization with the right to rule but without effective authority. The existence of authority is not purely a question of law but also one of fact. Of course, international law or the law of a given nation may recognize or validate a new government’s assertion of authority, but this has no effect on the new government’s status in relation to its people. Hart made this point when he argued that an English law declaring Tsarist laws to be the law of Russia would in no way change the fact that the Communist Party was the government of Russia.[119] It simply would mean that, in cases decided by English law that bear on Russian events, English courts would apply Tsarist law. We cannot resolve the question of whether a legal system continues to exist purely as a question of law.[120]

There are also moral reasons for recognizing the fact of the matter when a new government claims authority (and has effective authority). The moral quality of our relations with others depends on our ability to work out collectively what justice requires and to implement policies that reflect these collective decisions.[121] Seen in one way, the state provides an indispensable moral service: it provides authoritative solutions to coordination problems that otherwise would lead to disagreement and factionalism.[122] Through law, the state helps us to achieve what we have reason to achieve better than if we were to act on the balance of reasons that otherwise apply to us.[123] It does so in part by providing good answers to common problems (for instance when the government regulates dangerous substances) but even more importantly, it does so simply by providing a single answer when we might, in exercising our individual practical reasoning, come up with many reasonable but diverging answers. A state of nature is marked by a plurality of opinion, some of which may prove especially influential but there is no authority that can provide a single answer that is final. It is only a state that speaks for all of us that can close the debate on how to conduct our common affairs. To deny the authority of the new government is to deprive the people of this mechanism for coordination and, in effect, to thrust them back into a state of nature.

Adverse possession can be justified on analogous grounds. Adverse possession solves the moral problem of agendaless objects just as the recognition of a new government post-revolution solves the moral problem of a lawless people. The moral significance of adverse possession thus plays the role of ensuring that ownership serves its primary function.[124] The owner’s primary function in a system of property is to take charge of an object by setting the agenda for it. Within the constraints set by the government’s own agenda, owners have the authority to ignore the interests and opinions of others and to set what they think is a worthwhile agenda for the object in light of their own interests. The exclusive agenda-setting authority of owners does not require that others exclude themselves entirely from an object but rather that they act in harmony with the owner’s agenda or at least the agenda that the law imputes to her.[125] Ownership resolves conflicts not by keeping everyone except the owner out, but rather by ensuring that others defer to the owner’s decisions.[126] The effect of ownership is to provide a hierarchical structure for decision making about a thing: the owner, within the constraints set by government, makes the ultimate decisions about the agenda for an object and others—non-owners and subordinate rights-holders—must fall in line.

Ownership as a supreme position of agenda-setting authority thus avoids the potential for conflict among users that exists when there is no one clearly in charge of an object. If the original owner were to lack effective authority and the adverse possessor were denied de jure authority, there would be no authoritative resolution to questions about use with respect to that object. The function of ownership to coordinate uses of an object would be unfulfilled in that case. When there is a vacancy in the position of owner (because there is no one with effective authority), we are thrust back into a mini “state of nature” in our relations with respect to that object. The law of adverse possession is just one way of ensuring that there is always someone in charge in the eyes of the law, and thus no destabilizing vacancies. This is why the law validates the adverse possessor’s claims only where the owner can be shown actually to have lost effective authority. This is also why the owner defeats the squatter’s claims by showing that he continues to be in charge of an object. Ultimately, the law’s most pressing concern is not who is owner but rather that the office of owner is filled.[127]

B. Imperfect States, Imperfect Owners

The legitimacy of adverse possession, on this account, is not tied to the relative merits of the agenda that an adverse possessor sets for the object any more than the legitimacy of a government depends on the merits of each of its directives.[128] The aim of adverse possession is not to ensure that the most deserving user of the object owns it any more than a system of property generally guarantees that any particular owner has the best moral claim to own that particular thing. The morally relevant aspects of a squatter’s claim concern not the abuses of the original owner or her failure to set a sufficiently valuable agenda, but rather the original owner’s failure to occupy fully the role of owner.

I thus make no attempt to vindicate the adverse possessor on the basis of her moral standing as a conscientious revolutionary, one who stands outside the legal system to resist the bad exercise of authority by others. There are cases outside the law of adverse possession where squatters or others who challenge the owner’s authority do so in the manner of a revolutionary.[129] These are property outlaws: e.g., civil rights leaders organizing sit-ins in segregated restaurants,[130] squatters taking over vacant public housing en masse in London,[131] and environmentalists chaining themselves to trees in British Columbia.[132] The demands of a property outlaw, like those of the revolutionary, are not just to be put in the place of the owner but rather are for institutional change—change to what can be owned privately, change to how we define the scope of an owner’s authority, and change to the way in which entitlements are distributed. In the case of the property outlaw, the attack goes much deeper than a disagreement about the use to which the current owner puts the land. It is an attack on the very institutions that support the owner’s authority to do as she does. The property outlaw appeals to moral reasons to justify her attack on the system of property much as the conscientious revolutionary does for her attack on existing government.

The property outlaw, however, is not the paradigmatic case of the adverse possessor, and we need not justify adverse possession on similar moral grounds. We do not throw the original owner over for the adverse possessor on the grounds that the latter will do a better job any more than we reject the authority of the state on the grounds that it has not provided perfect guidance in all cases. Whether or not we allow for the possibility of revolutionaries to assert their own opinions of what is just and right, it would be much harder to make the case for the moral standing of a non-owner to act on her extralegal judgment about the quality of an individual owner’s tenure and his own suitability as a replacement. One reason is that this extralegal stance would undermine the function of a property system, which is to provide the assurances that allow a person to set the agenda for an object of property without attending to the opinions of others.[133] It would be quite another matter if a system of property were meant to guarantee the best possible agenda for a resource or to direct objects to their highest-value user.[134] The conscientious adverse possessor might then declare that he is morally justified in helping along the ends that justify the system of property, assuming that he can get a judge or some other official to agree that his agenda for the land represents a more valuable use than that of the original owner. Owners who have exercised their authority badly, by failing to select the highest-value use of land, ought not to be (and in law are generally not treated as) more vulnerable to adverse possessors than those who have exercised their authority well. The adverse possessor thus looks very little like the conscientious revolutionary on my account and much more like the leader of a coup d’état, whose reasons for assuming power may well be opaque to those from whom it demands recognition as the new government.


Immanent in a model based on inconsistent use is both the conceptual basis for distinguishing between owners and adverse possessors (lacking in the recent English approach to adverse possession) as well as the theoretical basis for overcoming the moral paradox of deliberate adverse possession (missing from the consensus American view). Rather than land theft, adverse possession is more akin to a bloodless coup d’état, in which a new ruler ousts the old office holder and steps into her place. Just as the leaders of a successful coup d’état turn into a new government that has authority over its subjects, so too is a successful adverse possessor retroactively transformed into an owner and immunized on this basis from liability for her initially wrongful invasion of another’s land. The rehabilitation of the adverse possessor avoids vacancies in the property system just as the rehabilitation of the new ruler following a coup d’état maintains the possibility of political authority and so civil society.