I. THE BASIC IDEA OF LEGAL POWER

Legal powers have been a topic of inquiry for a long time. Jeremy Bentham, John Salmond, Wesley Hohfeld, H.L.A. Hart, Joseph Raz, and many others discuss them. Since Hohfeld's workFootnote ¹ especially, they are mentioned in hundreds of articles and books about the nature of legal relations and legal rights, about private law, and about many other legal problems. And yet their distinctive features are not as well appreciated as they ought to be in current legal scholarship, and in particular in contemporary private law theory. In what follows I want to bring out some of these distinctive features in order to highlight the quite special role that powers play in the law. My hope is that an appreciation of these distinctive features will bring us to a better understanding of some difficult and persistent legal questions. I concentrate on private law powers, and the questions that I suggest a better understanding of powers can help to answer are private law questions. This is for two reasons. First, because private law is the area I know best. And second, legal powers seem particular salient in private law because private law's recognition of power in the hands of private individuals seems central to its conception of such individuals as persons (or as, take your pick, sui juris, small-scale sovereigns, or self-originating sources of valid claims). I do not say very much at all about other sorts of legal powers, such as public law powers or international law powers, but nothing I say here is meant either to preclude or to endorse the application of my arguments beyond private law.Footnote ²

To bring out what I argue are the most important features of legal powers, I employ and concentrate primarily on two powers: the power to acquire property and the power of consent (to some act that absent such consent would constitute a legal wrong). I choose these because in their centrality and importance they bring out the centrality and importance of legal powers more generally, and also because it is possible to discuss them without presuming any deep familiarity with private law on the part of the reader. But it is also important to remember that legal powers are pervasive throughout private law. The list of the powers that Hohfeld discusses in his article gives an idea of their diversity as well as their importance. He mentions, in addition to acquisition of unowned objects, abandonment of personal property, transfer/sale/disposition of property, revocation of gifts made causa mortis, the “right of re-entry,” and offer and acceptance in contract.Footnote ³

Now, the first thing to notice about powers, as this list exemplifies, is their second-order character: the exercise of a power operates on legal rights, duties, and so on (by changing them or creating them or ending them).Footnote ⁴ But perhaps the most crucial feature of legal powers lies in the way in which they change the legal situation. Changes in legal rights and duties can be brought about without the exercise of a legal power, but legal powers bring about such changes in a quite distinctive way. Contrast the following two cases. In one, I exercise a power to consent to your entry into my home when I invite you over for dinner. The exercise of this power changes what would be a trespass into a rightful visit. In the other, I convince my neighbor to invite you to dinner at her home (by regaling her with stories about your charm as a dinner guest, say). Her home is not my home, so I have no legal power to consent to your entry. I can bring about the change (from trespassing to rightful entry) only in the nonlegal way (of convincing her to invite you).

As we will see below, explaining just what the difference is between these two cases is not a simple matter. But it is absolutely crucial to understanding legal powers and their role in private law. Private law gives us a sort of clue about what is happening in the way that it characterizes what is required to exercise some paradigmatic powers. To exercise the power to acquire property, for example, one “manifests an unequivocal intention of appropriating” the unowned thing.Footnote ⁵ Consent in private law must be established by “overt acts and manifestations [of] feelings.”Footnote ⁶ To take another important example, entering into a contract requires “a manifestation of intention to act or refrain from acting in a specified way.”Footnote ⁷ On its face, the law seems to be saying that powers are exercised through the manifestation or, as I put it, communication of an intention to change the legal situation in the relevant way.Footnote ⁸ Look again at the two cases. To change your legal situation with respect to my neighbor's home, I need to do something that causes her to license your entry. By contrast, I can change your trespass into a rightful entry merely by communicating the intention to do so, without any intermediate causal process needing to take place. I call the difference in the way that your legal situation changes in these two cases the central distinction. In Section II I expand on this at length and explore various ways we might understand the central distinction and the way that the exercise of a legal power brings about legal change.

Another feature of legal powers on which I concentrate is brought out by reflecting on the question of whose legal situation is changed by the exercise of a power. A power-holder's exercise of the power affects the legal situation not only herself but also of someone else (the holder of the correlative liability, in Hohfeldian parlance). By acquiring an unowned object, I not only gain rights in it but also impose duties on others not to interfere with what is now my property; by consenting to your entering my land, I lose the right that you not enter, and you gain a corresponding liberty to enter; and by forming a contract, we mutually modify our rights and duties as between one another. At least in private law, powers are shot through with the pervasively bipolar or bilateral or correlative normativity that on many accounts is characteristic of private law.Footnote ⁹ This fact, combined with the fact that exercises of legal powers bring about changes in the legal situation in some distinctive noncausal way, has the implication, I suggest, that whatever it is that constitutes the exercise of a power must be something that is at the same time about both the power-holder and the liability-holder. That is, because A's exercise of legal power over B changes both A's and B's legal situation, the kind of fact that could constitute the exercise of that power must be a fact about both A and B. The law's notion of the communication of an intention to bring about the legal change is perfectly suited to play this role. As I show below in Section III, this notion makes the exercise of a legal power turn on a kind of a fact that is public as between power-holder and liability-holder.

Putting these two ideas together, the argument in Sections II and III is that A has legal power over B when A can change B's legal situation merely by communicating the intention to do so. Finally, in Section IV I turn to showing how this account, which is by and large motivated by quite general theoretical considerations about the sort of things that powers are and their role in our legal lives, provides concrete answers to legal questions about how to understand various private law powers. Many of these questions, as we will see below, center on the role of subjective psychological facts about the power-holder and the extent to which certain such facts are constitutive of the exercise of the power. For the kinds of reasons I briefly mention in the previous paragraph, I argue that these subjective psychological facts could not be constitutive of the exercise of the power, which is a juridical event.

II. THE CENTRAL DISTINCTION

Understanding legal powers requires us to understand the distinctive way in which powers allow us to bring about changes in our legal rights, duties, privileges, and so on (that is, in what I call our legal situation). Seeing how powers are distinctive in this respect is easiest by drawing the central distinction between the way in which we change our legal situation through the exercise of legal powers and the way in which we are able to change it otherwise. I draw this distinction in the previous section by contrasting two ways in which a legal change can be brought about. Before we examine it in detail, it is important to pause here to focus on just how important the distinction is.

One way to see this is by imagining what a legal system would look like without powers. I take it that in such a legal system we could still have rights and duties. But those rights would necessarily be quite limited. They would include only what Kant calls “innate right” as opposed to “acquired right”: we would each have (only) the basic tort law right that others not interfere with our person and each owe the correlative duty to everyone else.Footnote ¹⁰ Without powers we would be unable to modify our legal situation (or, what amounts to the same thing, the legal situations of others). We would be unable to acquire new rights through the acquisition of property or through others’ promises to us, so there would be no law of property and no law of contract. And conversely, we would be unable to incur duties to others through consenting to acts that would otherwise infringe upon our rights or through agreeing to do things for them.Footnote ¹¹ It is important to notice that in such a world, we would be able to act in ways that caused changes to our legal positions. But we would do so only either by changing the nonlegal facts of the world or by committing wrongs. By picking up an apple, I could impose upon you a duty not to interfere with it, but only because interfering with it would count as interfering with me, so the change in the legal situation would be merely the causal upshot of a change in the nonlegal world, the application of an unchanged norm to an empirically changed world. Powers seem to work differently. In exercising legal power, we change our legal situation just by doing so, that is, without needing to change any nonlegal features of the world.Footnote ¹²

The central distinction is hard to pin down for a few reasons. For one thing, the law is rife with situations that can lead to a confusion about where it should be drawn. Contrast a case where A contracts with B to deliver some widgets with a case where A represents to B that A will deliver them and B relies on the representation. In either case, should A fail to deliver, he might be subject to liability and the amount of damages might even end up the same. But in the first case, A's liability arises from the exercise of a power (to contract), whereas in the second case it does not. Getting clear on the difference between these cases is hard without a clear understanding of powers. Moreover, some attempts to characterize legal powers are framed in a way that obscures this crucial distinction.

Take Hohfeld, for example. His view is that A has power over B when a change in B's legal situation results from a fact “under the volitional control” of A.Footnote ¹³ It looks on its surface as though A's liability in both of the above cases is grounded on facts under A's volitional control (his decision to enter the contract with B or his representations to B), and indeed the most natural reading of Hohfeld's language here seems to capture a much wider set of cases than we would normally want to capture with an account of legal power. To borrow an example from Raz, the decision to move house is under my volitional control in Hohfeld's sense, and when I do move house, my legal rights and duties change in various ways. But we do not want to say that by moving I exercise a legal power.Footnote ¹⁴ Why not? Beyond the case-based intuition, the explanation is that the changes in my legal rights and duties that result from my moving house are not brought about in the same distinctive way as changes are brought about when I exercise legal power. Roughly, it seems that nothing normative has changed but rather that the unchanged norms (or laws) apply to a world changed in some empirical way (I used to live here but now I live there).

In addition, we use the word “power” to describe both situations in which a legal power has been exercised and situations in which it has not. Recall the example I introduce in the first section. I have the legal power to change what would be a trespass into a rightful visit by inviting you to my home for dinner. But I might also be said to have power to bring about a parallel change insofar as I can convince my neighbor to invite you to her home. Of course, in the latter case, I do not have any legal power with respect to your being invited over. But we might nevertheless want to talk about both as cases in which I have power with respect to your invitation because in both it makes sense to say that you were invited over because I wanted you to be. Raz marks this contrast by differentiating legal power and what he calls “power as influence.”Footnote ¹⁵ But even though in both cases we can say that you were invited over because I wanted you to be, an ambiguity in the word “because” masks a very significant difference between the cases, a difference that has to do with the way that my action (or desire) could bring about or explain the legal change. In the case of power as influence—what I have over my neighbor—I cause the legal change to come about, but in the case of legal power, something different is going on. So the use of the English word “power” can sometimes lead to confusion about the central distinction.

Of course, the most important reason that the central distinction is so hard to pin down is that it is not at all clear how to characterize the nature of the explanatory relationship between the exercise of a legal power and the change in the legal situation it brings about. While H.L.A. Hart is most closely associated with legal powers for his discussion of power-conferring rules in The Concept of Law,Footnote ¹⁶ he discusses powers on their own terms in more detail in his consideration of Bentham's account. Bentham's own views are complex and problematic enough that it is not worth our while to discuss them here. But Hart crucially saw that Bentham's analysis suggested that the effects of the exercise of legal powers are “legal normative effects or consequences, not natural effects. The point is not that the use of such words causes later effects or events to be done or to happen.”Footnote ¹⁷ Here Hart draws the central distinction by seeing that legal changes brought about through the exercise of legal powers are not brought about causally.

This is a promising idea. Recall once again our two cases of your being invited over for dinner, and start with the case of my neighbor's home. Assuming I do convince her invite you over, we can ask how it is that my action brings about or explains the relevant legal change. It looks as though what has happened is that in singing your praises as a potential dinner guest to my friend, I caused her to invite you. Here the causal relationship between my action and the invitation runs through the way my action has manipulated the nonlegal facts of the world (and in particular my friend's mental states). This relationship would be no different from the causal relationship between the invitation and any of the following: my friend's needing a fourth for her weekly bridge game, my friend's wanting your interior design advice, my friend's sister asking to be set up on a blind date with you. In all of these cases, an event takes place that causes my friend to decide to invite you over. These are all straightforward instances of everyday causation, in which some event's occurrence changes the circumstances of the world (and in particular some psychological facts) in a way that results in my friend's coming to a decision.

But in the case of my own home, things are rather different. Here the difference between the legal situation before my action (i.e., before the invitation) and after my action is not, at least not obviously, explained by reference to causation. My exercise of my own legal power to invite you over changes the legal situation—transforming what would be a trespass into a licensed entry—in a way that no other action could do.Footnote ¹⁸ By inviting you over, I have not caused it to be the case that you are now licensed to enter whereas before you were not. Rather, it seems that the exercise of my power explains the legal change in some other (again, noncausal) way.Footnote ¹⁹ Raz's well-known account tracks this same distinction. Raz says that legal powers bring about legal changes “normatively and not causally.”Footnote ²⁰ Again we see the idea that legal powers do not cause legal change but bring it about or explain it in some other way. It is not entirely clear what it means to say that the exercise of a legal power brings about legal change normatively, but Raz further cashes the difference out by reference to the distinction between an act's results and its consequences, which he takes from Anthony Kenny. Here is what Kenny says:

Raz says that when A exercises a legal power, the result of A's action is the legal change, but when A exercises power as influence, the legal change (if any) is just the consequence of it. Kenny's suggestion that the contrast is between a causal relation and an intrinsic relation brings out the thought that the form of explanation appropriate to our task seems to require something of a different sort of metaphysical relation from causation. We can say that a result happened because an act did, and we can also say that a consequence happened because an act did. But these are two different kinds of explanations.Footnote ²² The second “because” is the “because” of causation, but the first “because” is not. The act did not cause its result, on Kenny's understanding, because the result is in some sense a part of the act; it “defines,” in a way, whether or not the act has occurred.

This suggests, as Hart saw, that what we need is a quite general idea of noncausal explanation. The recently philosophically popular notion of grounding seems to be onto the same idea.Footnote ²³ Sometimes some Y facts are explained by some X facts in that the X facts cause the Y facts: the fact that the sun has risen explains why the temperature is going up. But sometimes explanation does not take this causal form. The fact that the page is red explains the fact that the page is colored but it does not seem to have caused it. Rather the page is colored in virtue of the fact that the page is red. The fact that I harmed you explains why my action was wrong but it did not cause it to be wrong. Instead the harmfulness of the action grounds its wrongfulness. The idea is that something similar is going on with the way in which the exercise of a legal power explains the occurrence of the relevant legal change: the fact that I invited you over explains the fact that you will not be trespassing when you enter, but it does not cause you not to be trespassing. In other words the exercise of the power grounds the legal change.

It seems plausible to suppose that at base all these different ways of cashing out the difference between legal power and power as influence are all grasping at the same idea. Whether we say that the exercise of a power brings about the legal change normatively, or that it grounds the legal change, or that it explains it noncausally, or that the legal change happens in virtue of the exercise of the power or depends on the exercise of the power, it seems we are aiming at the same basic idea. Although we lack a clear and unquestionably illuminating way to describe the phenomenon, we might nonetheless think we have a grip on the difference between how my invitation explains the fact that you are not now trespassing when you are at dinner at my home and how my description of your charms to my neighbor last week explains the fact that you were not last night trespassing when you were at dinner at my neighbor's home. The way in which the contrast is so illuminating suggests that this might be one of those situations that Aristotle reminded us of, in which “one contrary state is recognized from its contrary,”Footnote ²⁴ so Hart's notion of noncausal explanation might be our best option. Assuming that it is, to grasp the central distinction, we need to understand this: while we can change our legal situations causally in any manner of ways, legal powers are distinctive in that they uniquely allow us to bring about legal change noncausally. We can turn now to looking at the implications of this thought within the correlative context of private law.

III. COMMUNICATION AND CORRELATIVITY

When I invite you over to dinner, I thereby exercise a power to change your legal situation so that you are no longer trespassing when you enter my home. According to what is shown so far, what is distinctive about this process is that the exercise of the power—the invitation—explains the legal change noncausally. Now I want to focus on something else. It not only changes your legal situation; it also changes mine. Having invited you over, I no longer have the right that you not be at my home (unless and until I revoke the invitation). There are complexities here, but at least this much is true: once I have exercised the power, it becomes the case that merely by standing in my dining room, you are not wronging me. So both of our legal situations are changed by my exercise of the power. This fact has significant implications for our understanding of powers in private law. It is plausible to suppose that if the change in the legal situations of both the power-holder and liability-holder is brought about by the exercise of a power noncausally, then only certain kinds of facts could explain that change. In particular, it seems as though the change must be explicable in virtue of some facts about both parties, because some fact entirely about one of them is a poor candidate to explain noncausally a change in the other's legal situation. Both the power-holder and liability-holder are star players in the drama that constitutes the exercise of the power. I argue below that this is why the law insists that the exercise of legal powers be brought about through an act of communication by the power-holder to the liability-holder of an intention to bring about the legal change. Thus the power must be exercised through an event in which they are both participants.

To begin in somewhat abstract terms, consider again the juridical event that comprises the exercise of power in a paradigmatic, unproblematic case. B wants to enter A's land; without A's permission, this would be a trespass, but A can exercise a power to consent to this entry. Suppose that A wants B to enter and wants to exercise her power. What must she do in order to do so? A's trying to exercise her power by simply intending that B not be trespassing is not enough. Nor would it be enough if B happened to guess what A was thinking and entered on that basis. In this simple case, it seems that the power has this feature: when A intends to consent and B recognizes that A intends to consent, A has consented. What brings the power-exercising event about is the recognition by B of A's intent to bring it about.Footnote ²⁵ But just as this is not just a matter of A's intention, it is also not just a matter of B's knowledge: if A secretly intends to let B enter and tells this to C, and C tells it to B, A has not consented. And this suggests that the exercise of the power involves more than A's intention and B's knowledge of that intention. It involves rather a single event that makes reference to both of these: it requires B's coming to be able to know about A's intention through A's manifestation of that intention. It requires that A communicate her intention to B, where “communication. . . is a relation between people,”Footnote ²⁶ so that the communicative act is public as between A and B. This communication, we might say, is something that A and B “do together.”Footnote ²⁷

The power is exercised through a single juridical event that cannot be conceived of by reference to some facts about A alone, or some facts about B alone, or indeed some facts about A alone and some facts about B alone. Rather, the power is exercised through an event—A's communication of intention to B—that must be understood in terms of A and B and the relationship between them. Thus the exercise of power in this paradigmatic case invokes the correlatively structured normativity that is characteristic of private law. Just as a wrong in tort law is constituted by a single juridical event of which plaintiff's doing and defendant's suffering are two correlative aspects,Footnote ²⁸ the exercise of a power is constituted by a single juridical event (communication) of which the power-holder's manifesting an intention and the liability-holder's recognition of the intention are two correlative aspects. In both cases, the relevant juridical event is one that situates the two parties equally as opposing poles of the correlatively structured juridical relationship and thus vindicates their equality as participants in the legal transaction.Footnote ²⁹

This basic notion of power as requiring communication is consistent with (and indeed an elaboration of) the law's own internal conception of what it is to exercise a power. To exercise the power of consent, a power-holder must communicate the intention to render nonwrongful conduct that would otherwise be a trespass or battery.Footnote ³⁰ To exercise the powers of offer and acceptance, contracting parties must manifest the intentions to enter into the contract.Footnote ³¹ And to acquire property, one must communicate the intention to become its owner.

My intention to capture a fox running by in the woods is not enough to change the rights and duties of anyone else. I need actually to capture the fox to do that.Footnote ³² Carol Rose says that my act of capture can be seen as a form of communication (or “statement”) of an intention to capture the fox and to change the legal position of myself and everyone else.Footnote ³³ Rose takes the idea from Blackstone, who thought that a first possessor's “taking amounts to a declaration that he intends to appropriate the thing to his own use.”Footnote ³⁴ As Kant puts it, acquisition involves “Giving a sign (declaratio) of my possession of this object and of my act of choice to exclude everyone else from it.”Footnote ³⁵ And this is precisely how the power of acquisition is to be understood. My capture of the fox communicates the intention thereby to become its owner (the animus possidendi), and the communication brings about that legal change: I become its owner, and everyone else now owes me a correlative duty not to touch/take/damage the fox.

Rose's account of acquisition also helps us see that different communicative acts will be fitted to different powers. The thought that taking physical control amounts to the act that communicates an exercise of the power of acquisition seems odd for two reasons. First, why should acquisition be required to communicate? Here we can clear things up by supposing, contrary to fact, that different act of communication could suffice. Why can I not acquire a fox, that is, by pointing at it and saying “mine”? The answer has to do with the fact that power to acquire is an in rem power, such that when I exercise the power and acquire the fox, I impose a duty on everyone else not to interfere with it. Thus I need to communicate to everyone else. That is, it must be an act that communicates my intention, again in the sense of making it public and recognizable, to everyone,Footnote ³⁶ or, as the court in Pierson says, it must be “unequivocal.”

For in personam powers, A's communicative act must be understandable as one that is public as between A and B. For in rem powers, the requirement that A's act be public as between A and all other Bs just means it must be public. Once we see that, we see that the only way to communicate my intention to acquire the fox in a way that will be sufficiently public is actually to capture the fox.

Second, why think that acquisition is about communication and not just physical control? Here the decision in Pierson is helpful. The court tells us that “actual bodily seizure” is not in fact required, but that “encompassing and securing such animals with nets and toils, or otherwise intercepting them in such a manner as to deprive them of their natural liberty, and render escape impossible” is enough.Footnote ³⁷ By catching a fox in a trap that I have set in the forest, though, I obviously do not have physical control of the fox vis-à-vis others (who could come and take the fox out of the trap when I am not there); rather what I have done is entirely normative, an act that, as the court says, “manifests an unequivocal intention of appropriating the animal.”Footnote ³⁸

This last point brings us to the thought that different forms of acquisition require different forms of communication. We can interpret the law of first possession as telling us what acts are required to communicate the intention to acquire ownership in various kinds of unowned objects (noting in particular that actual physical capture is not always required),Footnote ³⁹ and something similar can be said about intellectual property.Footnote ⁴⁰

Then we can broaden the inquiry further, and questions will arise about just what acts constitute the communication that amounts to the exercise of any given power. The answer is that the law decides. That is, not every act that we might pretheoretically think of as communicating an intention will suffice to exercise the power; that was the lesson of the fact that just saying “mine” will not count as communication in first-possession cases. This is an important aspect of the role that communication plays in the account of powers. Moreover, the law decides what counts on a power-by-power basis. The point is made by Raz in pointing out that legal powers are often exercised by what Grotius called “certain mute signs,”Footnote ⁴¹ that is, “special ceremonial or formal acts as in making a deed or getting married,” “weighing of metal on scales and its transfer from buyer to seller, or walking along the borders of the land bought”: these acts are ceremonial and formal to ensure their suitability as distinctively public communicative acts.Footnote ⁴² Only legally recognized communicative acts will suffice to exercise a power. Although Raz's account of powers is not framed in terms of communication, his account does provide a helpful general guide to the way that the law indicates the nature of the acts that will count as communication in the requisite way:

In my terms, this passage tells us that people will not standardly catch foxes unless they want to acquire ownership in them, or sign deeds unless they want to transfer title in land, or say “I do” standing at the front of a wedding unless they want to get married, so the law picks out these acts as the communication or sign or declaration of the intention to make those legal changes.Footnote ⁴⁴ And this is important because the objectively reasonable nature of these acts as indicative of the presence of the relevant intention means that they are well placed to serve the role of making the exercise of the power public as between power-holder and liability-holder. That is, acts that reasonably would not be performed in the absence of the power-holder's intention to bring about the legal change are well suited to indicate publicly as between power-holder and liability-holder that the power is being exercised.

This last point helps emphasize, once more, that the act that counts as exercising the power must be an event that is public as between the parties. This is important because it helps us to see that the communication requirement is not simply about making the power-holder's intention known to the liability-holder. The requirement of publicity as between the parties manifests itself, typically, in a requirement not of knowledge but of knowability. A's power over B is not exercised when A intends to bring about the legal change and B comes to know about A's intention through some means other than A's communicative act.Footnote ⁴⁵ So suppose that A intends to license B's entry onto A's property and tells this to C, who then tells B about it. A has not exercised any legal power, and B would still be trespassing were she to enter A's land. The law is consistent with this. In general B has no defense to a trespass action brought by A if B gets putative permission to enter A's property from someone other than A.Footnote ⁴⁶ To the same effect is the phenomenon of so-called “ghost surgery,” where A consents to her doctor, B, performing a surgery which is then performed by C after B purports to license B to perform it. Here A has a claim in battery against C even though C performed exactly the surgery that A wanted done, and no harm resulted.Footnote ⁴⁷

This is a crucial point. It helps us to see that the requirement of A's intention and the requirement of B's knowability are not two distinct requirements joined for external purposes but rather that one and the same juridical event must constitute both the manifestation of A's intention and the recognition (or availability for recognition) by B in order for that event to constitute the exercise of a power. When A intends to bring about a change in B's legal position and B recognizes (or is able to recognize) this, neither the intention nor the recognition counts independently of the other. The intention is significant only because of the recognition that is correlative to it, and vice versa. These two elements in the exercise of the power are two sides of one single juridical event.Footnote ⁴⁸

The idea that legal powers are exercised through communication indicates why it is a mistake to think, as some recently argue that we should, that the relationship of ownership is best understood in terms of a power that owners have over others “to change (in some nontrivial measure) the rights and duties that nonowners have toward the owner with respect to an object.”Footnote ⁴⁹ While of course ownership involves powers (in particular the power to consentFootnote ⁵⁰ and the power to transfer), it is simply wrong to think that the primary legal relation between owners and others is a power. The basic juridical feature of ownership is that owners have a right that others not enter their property.Footnote ⁵¹ As this is a private law right, the right includes in the normal case the power to waive or consent to acts that absent consent would constitute infringements. But it is crucial to see that the right is paramount here. One way to see this is by noting that nonowners have a duty not to enter others’ land, and not merely a liability (which would be what they had were ownership to consist in a power).Footnote ⁵² When I enter your land absent permission, it is a trespass even if you have never communicated that to me, and indeed, even if you or I or both of us do not know who the true owner of the land is.Footnote ⁵³ That is, no exercise of a power is required to make me a trespasser on your land. Quite the contrary; the exercise of a power is required to make me not a trespasser on your land.

The correct understanding of the role of communication in an account of ownership thus helps to bring out the core features of legal powers. Since the exercise of a power brings about a legal change in the situation of the power-holder and liability-holder noncausally, it must be accomplished by an act that does not depend on either of them taken singly but rather is about both of them, an act that is public as between them. The law's conception of powers as accomplished through communication serves this role. In the next section I turn briefly to some discussion of the communication requirement and its relation to some questions about the role of the subjective intentions of the power-holder in the exercise of a power.

IV. POWERS (AND INTENTION) IN PRIVATE LAW

In the previous two sections, I highlight what I take to be the central salient features of legal power in private law. First is the central distinction, the idea that legal powers allow us to change our legal situations noncausally. It is the exercise of legal powers in this distinctive way that allows us to acquire property, to enter into contracts, to consent to acts that would otherwise wrong us, and to perform and participate in many other legal activities that are at least partially constituted by legal powers so understood. I also highlight the fact that because of the correlative normativity of private law, legal powers so understood must, at least in private law, be exercised through an act of communication of the intention to bring about the relevant legal change, because only communication can provide a way for the change to be brought about noncausally for both the power-holder and liability-holder. In this section I want to show how understanding legal powers in terms of communication of an intention to bring about a legal change helps to clarify a set of persistent questions about various parts of private law.

The set of questions I have in mind largely revolves around whether a party's subjective intention—her actual mental state—matters in determining some legal question about powers in private law, such as whether A and B have formed a contract, whether A has consented to B's entry on A's land, whether A has given her property to B, and so on. The suggestion will be that a proper understanding of powers, consistent with the considerations discussed above, gives us a theoretical reason (as opposed to case-by-case intuitions) to think that most of the time the exercise of a legal power does not depend on the subjective intentions of the power-holder.Footnote ⁵⁴ As I argue above, the communicative act that is constitutive of the exercise of a power is a correlative event, one that takes place at the same time for both A and B such that they are both equal participants in the legal change. Once we see this, we see that it is highly implausible to think that facts about one of A or B's subjective mental states can play a role, as these are facts that are entirely about the person whose mental states they are.

So the basic thought is that to exercise a power, a power-holder must communicate the intention to bring about the relevant legal change. It is generally uncontroversial at law that there is no requirement that the power-holder have an intention to act consistently with the change in question: I can contract without ever intending to perform the contract.Footnote ⁵⁵ But what is a matter of controversy—or at least unclarity—is whether the power-holder must intend to bring about the change or merely communicate the intention.Footnote ⁵⁶ For example, the orthodox view says that the common law of contract allows that one can contract unintentionally if one communicates or manifests the intention to contract.Footnote ⁵⁷ But there are dissenters, and in civilian jurisdictions, subjective intention is required.Footnote ⁵⁸ Contract formation is a difficult and deep problem, but on the understanding of powers that I offer here, the orthodox view must be correct: the formation of the contract affects both parties and so must be constituted entirely by facts that are public as between them and not by facts that are entirely about one of them (such as their internal psychological states).Footnote ⁵⁹ As shown above, at private law, subjective intention is not required to exercise the power of consent; by communicating an intention to render some touching (or some entry onto land) nonwrongful, I have exercised my power to do so even if I did not actually want to do so.Footnote ⁶⁰ The reason for this is that the relevant legal change—the rendering nonwrongful of some act that otherwise would infringe upon a right of mine—affects not just me but also (say) you, and so it must be explained by some fact that is not merely about me (or merely about you) but about both of us, and the communication of my intention is just such a fact.Footnote ⁶¹

There are many powers involved in the law of property. I discuss the power of acquisition and the power to consent to entries that would otherwise be trespasses in the previous section. Another central power in the law of property is the power to transfer.Footnote ⁶² Generally, it takes two to transfer. Transfers of property can be accomplished through contract (as per above), as well as through testamentary dispositions, where it is clear that the subjective intentions of the testator do not matter if they conflict with what was communicated.Footnote ⁶³ Transfers can also be accomplished through gift. In England, no subjective intention is required to exercise the power of gift, but in Canada and the United States it seems things are different.Footnote ⁶⁴ Another power that seems to require subjective intention is the power to abandon property.Footnote ⁶⁵ If subjective intention is required in these cases, it is easy to see why: it is merely an evidentiary requirement, as the acts that constitute communication of the relevant intention (respectively, handing the object over, leaving the object behind) allow too easily for ambiguity, so a subjective intention requirement might be added in order to attempt to resolve such ambiguity. However, these minor exceptional cases aside, the law of property is consistent with the account of powers I defend here.

When attempting to understand the role of subjective intentions in various private law powers, we ought to look first and foremost to the fact that these are powers. And powers play a special role in private law. As I endeavor to demonstrate here, powers have two central features that make them important and distinctive. They allow us to change our legal situations noncausally, and so vastly expand our control over our rights and duties and thus over our legal relations with one another. And this noncausal mechanism means that, in private law's correlative context, they are exercised through acts of communication of the intention to bring about the relevant change, as in the law of consent's insistence on manifest consent or the law of acquisition's requirement that a first possessor unequivocally manifest an intention to possess. These considerations apply across private law powers. They help us to resolve disputes about particular powers by appeal to high-level theoretical concerns about the nature of private legal personhood. But they also help us to see just what sort of thing private law is and what sort of beings persons are, for the purposes of private law. As such, attention to legal powers in private law can be nothing but rewarding.