Article body


The legal maxim, “no one is to be regarded as the owner of his own limbs,” has a long pedigree in the common law, and in Roman law before that.[1] On this view, the body is res nullius—nobody’s thing.[2] In the common law, this rule has its origins in eighteenth and nineteenth century criminal prosecutions concerning the treatment of corpses.[3] The rule has since transcended those origins; it has been consistently applied in civil disputes concerning body parts, even where these disputes concerned the separated body parts of living persons. Recently, however, this long-standing legal orthodoxy has softened. Courts have begun to allow for property in body parts. But the law still insists that the body as a whole is res nullius; body parts must be separated from the body to become res.[4] I call the view that separation is morally transformative in this way the “Separation Thesis.”

This prompts (at least) two interesting questions. Why think that separation from the body is normatively transformative in a way that the law should track? And what would be gained or lost by allowing for property in attached body parts? In this paper, I argue that the law has good reason to recognize property rights in (some) body parts, attached or not. In doing this, I reject the Separation Thesis. Others have argued that personal rights[5] may stretch beyond our bodies to include objects such as prosthetics and wheelchairs.[6] Here, I argue that there is a second frontier between personhood and property, viz., within our bodies. There can be property in body parts, and personal rights in things outside the body. All of this scrambles the intuitive alignment of our persons with our bodies, and property with the “outside world.”

I proceed as follows. In Part I, I canvass the best arguments for the Separation Thesis: first, that tangible property must be possessable to be ownable, and that only separated body parts can be “possessed”; second, that property is essentially alienable, and body parts are inalienable until separation; third, that owners and what they own must be distinct, meaning that owners cannot own parts of themselves; and fourth, that only those body parts that have no ability to reunify with the body become property upon separation. The prospect of reunification (or lack thereof) is thus revealed by separation. I argue that, on closer scrutiny, none of these arguments succeed. If separation from the body is not morally transformative, and we can have property rights in detached body parts, then we can have property in our bodies. In other words, less than the entirety of my body is me, and the rest is mine. In Part II, I argue that this position is also normatively attractive because it grounds a right to the parts of our bodies that are not necessary to our being separate moral agents, and explains why certain “artificial objects” that fulfill bodily functions can become a part of our persons. In Part III, I turn more directly to private law. I show that this view lucidly captures both the proprietary and personal wrongs one commits when one excises a body part from another’s body without their consent. As a result, this account offers a clearer way to address legal disputes concerning body parts than the existing jurisprudence, a claim I develop in Part IV.

I. Separation and Separability

I have discerned and developed four credible arguments for the proposition that something of normative significance occurs when a body part is detached from the body, such that the body part can thereby become the subject of a property right.[7] Let me preface my discussion by clarifying what exactly these arguments must show. At present, the law insists that I cannot own my body part until that body part is separated from me.[8] The law also makes separation a sufficient condition for ownership of a body part; once separated, something “ownable” comes into being.[9] In this way, as Christopher Essert helpfully analogizes, the law treats the separation of a body part from a whole body as akin to the birth of a wild animal or a meteor hitting earth.[10] So, we are in search of an argument that will explain why actual separation from the body is both necessary and sufficient for property in body parts.[11] My primary purpose in developing these arguments is to show that they do not actually vindicate the Separation Thesis.[12] At the same time, discussing these arguments will yield important insights useful to developing the idea that there can be property in our bodies. Seeing just how these arguments err will be worth our while.

A. Possession (Or Lack Thereof)

Why might separation make a difference? One thought is that body parts must be possessable to be ownable; but when a body part is attached to one’s body, it is incapable of being possessed. In R v. Bentham, Lord Bingham marshals this point, writing: “One cannot possess something which is not separate and distinct from oneself. An unsevered hand or finger is part of oneself. Therefore, one cannot possess it.”[13] This argument has an intuitive ring to it. When I move my body, all of it comes along with me. I don’t do anything without my body. This suggests that I do not really possess my body parts, including my fingers.

Let me develop the thought from Bentham a little further before offering a response. Possession seems conceptually different from my relationship with my body in the following respect. Possession can be contrasted with periods of non-possession. Roughly, I can only possess something if there are possible occasions where I do not possess it. In this way, the law seems to track an ontological separation between me and what I can possess, such as my pen. I am not in physical contiguity with my pen at all times, and that is precisely what makes my pen capable of being possessed. The occasions in which I do not possess my pen reveal this. In light of this Bentham-ite thought, the law’s insistence on separation looks less mysterious. Separation changes a body part from res nullius to res because body parts become capable of being possessed when separated. For instance, I can hold my severed finger in (what is left of) my hand.[14] Possessing my finger in this way was impossible when my fingers were attached to my hand.

Plausible as this sounds, I think this development of Bentham does not vindicate the Separation Thesis. The reflections above do suggest that separability is a necessary condition for something to be ownable; that much in Bentham is true. Yet this does not mean that actual separation is the occasion at which some part of my body becomes something ownable. This is a point I will emphasize frequently in this section. Actual separation is neither necessary nor sufficient for property in body parts.

To see that separation is not a sufficient condition for the creation of a property right, notice that a body part can be detached from my body without ushering in a change in the kind of right I have over that body part. One way to put this point is that personhood need not end at the biological limits of one’s body. When my finger is sliced off in a kitchen mishap, many would agree that I am the one who has the strongest claim to the finger.[15] I am the finger’s biological source, after all.[16] But this does not require that my finger become ownable. We could maintain that the finger remains a part of my person despite separation; this is, in fact, Essert’s view about the detached finger.[17] So, in general, separation underdetermines whether the right to a body part is “demoted” to a property right or remains governed by a personal right. Thus the view in Bentham does not tell us why separation should have moral significance as a sufficient condition for the creation of property rights in body parts.

Moreover, we should be wary of taking cues about what is ownable from the notion of possession. Recall the Bentham court’s argument. The court couches its reasoning as a series of conceptual claims about the nature of possession which syllogistically produce the conclusion that we do not possess our fingers. Yet the notion of possession is notoriously Janus-faced; possession has both a factual and legal meaning. On a lay, factual understanding, possession is a person’s relationship to a thing that is “characterised by a high degree of physical and mental control over the thing.”[18] Holding a pen in my hand looks like a core case of lay, factual possession. By contrast, where a legal rule decides whether one is in possession of something, then legal possession––possession in a technical sense––is at play. As Simon Douglas explains, legal possession is both broader and narrower than factual possession.[19] Legal possession can be far more expansive. Consider Dunwich v. Sterry, a case about a trespass action concerning a whisky barrel that had washed ashore.[20] The plaintiff held a franchise over objects washed upon the shore, and so had a property right in the barrel. The barrel was removed by the defendant. The case turned on whether the plaintiff, who had no physical proximity or even knowledge of the existence of the barrel, had “possession” of the barrel. The court found that he did, holding that his right to possess the barrel furnished him with a kind of constructive possession.[21]

Legal possession is also narrower than factual possession, in that normative considerations can drown out paradigmatic instances of physical possession. R v. Bass was decided at a time when criminal liability for theft required the thief to have removed the chattel from the possession of its owner.[22] Bass was given a package for delivery by his employer, but instead opened the contents and sold them at a pub. He was found liable for theft despite the fact that he had not removed the package from his employer’s possession; the employer, after all, had freely placed the package in his (factual) possession.[23] The lesson emerging from all of this is that holding a thing in one’s hands (or failing to do so) is orthogonal to a finding of legal possession.

This lesson in mind, let’s turn back to body parts, and the finger in particular. Notice that one enjoys a high degree of physical and mental control over an attached finger. In fact this seems true in virtue of the fact that the finger is part of one’s attached body; I have stronger physical and mental control over my finger when it is attached rather than severed.[24] Put differently, an attached finger is not the type of thing that is incapable of being factually possessed because it is incapable of being physically controlled, such as the Pacific Ocean.[25] Indeed, I exercise a high degree of control over my attached finger and can deny its liberty to move apart from me. Nor is my finger akin to my reputation, which seems incapable of being factually possessed precisely because my reputation is not a physical thing. A finger has physical extension whether attached or detached.

Because factual possession does not seem to rule out possession of my attached finger, perhaps the Bentham court’s reasoning is driven by some normative idea––and therefore some idea of legal possession––that posits that I do not possess attached body parts (because they are me). But if so, then the Bentham argument does not support the proposition that separation is a necessary condition for ownability. Bentham simply assumes that proposition. Notice that the Bentham argument’s first and second premises—that “one could not possess something which is not separate and distinct from oneself”[26] and “an unsevered hand or finger is part of oneself”[27]assume that the finger is a part of me and not mine when it is attached to my body. In this way Bentham does not offer an argument for the Separation Thesis, but rather uses the Separation Thesis as a premise in an argument aimed at a conclusion about possession. There is no a priori reason to believe that I cannot possess my finger, unless we are already committed to the view that the body is entirely res nullius.[28]

B. Alienability

The next important idea that might substantiate the Separation Thesis is that property is essentially alienable: property must be capable of being someone else’s.[29] The fact that property is essentially alienable can be turned into an argument against permitting property rights in body parts in two ways. First, to say that property is essentially alienable means, amongst other things, that who owns what property is a totally contingent fact. The fact that I own this particular MacBook is simply a feature of the fact that I entered into particular market transactions. I could have owned another MacBook, or no MacBook at all. Property law does not link me to any particular object of property. Put differently, no property has anyone’s name on it, a priori. This might be grounds to resist the notion of property rights in body parts precisely because it seems like every body part does have someone’s name on it (i.e., the name of the person whose body it is). Only when a body part is separated from one’s person do we introduce the necessary alienability for the body part to become ownable. Second, unlike the ease with which we alienate most property, alienating body parts is much more difficult. Perhaps this, too, militates against acknowledging property rights in body parts until they are separated. Let me take these arguments in turn.

James Penner’s discussion is a useful point of departure for the first idea. Penner explains that “if one stands in the relationship of owner to a thing, then it must be possible for someone else to own it as well.”[30] My jacket is mine today, but could be yours tomorrow. This is relevant to the Separation Thesis in the following way. One might contend that body parts that are separated from us are thereby shown to be only contingently associated with us. When we cut hair, we appear to divorce it from its source body, and thus introduce the relevant sense of contingency over who might own the hair, even if it is clear that the biological source presently owns the hair––suddenly the possibility of someone else owning my hair seems to come online. In sum, separation creates alienability, which in turn creates ownability.

This argument, again, does not challenge my contention that separation is itself normatively inert and that all the action is in separability. In fact, it may support that contention. Modern medicine has made previously unreachable caverns of the body vulnerable to excision. As Muireann Quigley puts the point, “Advances in medicine and the biosciences mean that a huge variety of biomaterials––from blood to tissue samples to whole organs––are both separable and regularly separated from persons.”[31] These developments mean that body parts meet the requirement for property under what Penner calls his “Separability Thesis”:

Only those “things” in the world which are contingently associated with any particular owner may be the objects of property; as a function of the nature of this contingency, in theory nothing of normative consequence beyond the fact that the ownership has changed occurs when an object is alienated to another.[32]

Accordingly, this first branch of the alienability idea––the contingency of who owns what––does not show that separation from the body is of unique moral importance. Rather it confirms that all the moral action is in separability, because that is what secures alienability.

Let me turn to the second gloss on the alienability idea, which concerns the process of alienation. One might argue that, even today, alienating my hair to you remains much easier than giving you my kidney. I can just snip off my hair and hand it to you, but some comparatively involved medical procedure is required to excise my kidney (or at least to do so safely).[33] This might, then, militate for the proposition that I cannot own my kidney. Is it a problem for the existence of property in my kidney that my kidney cannot be alienated as easily as my hair? Again, I don’t think so. Suppose I want to sell you my still-embedded kidney. Is it true that I must excise the kidney from my body in order to make you its owner? Because of current surgical realities, if you wish to physically possess your newly-acquired kidney, or implant the kidney in your body were one of your own kidneys to fail, that would indeed require me to undergo a medical procedure. But here too it is just separability that matters. We have no reason to think that property in my kidney only begins when it is actually separated from my body.[34] Now consider a further development of this example that prompts a different, more normatively charged worry. Suppose that one day, you want the still-embedded kidney to be sent to your home in New York City (say, in order to sell the kidney to a third party). I live in Toronto. This might prompt the concern that in virtue of your property right, you enjoy a derivative right to order me to New York or to give you the kidney on demand. Thus, your property right in my kidney might balloon into a power over my body that resembles slavery, or at least some gratuitous and unwarranted authority over my body.

This warrants two responses. First, notice that any derivative control conferred by your owning my kidney is not unlike an analogous situation involving a non-bodily chattel. Suppose I sell you my shirt while I am wearing it. I decide to keep the shirt on until further notice because you express no interest in taking it right away. When you call me to deliver the shirt to you by mail, I will have to take the shirt off, and in the process, contort my body in certain ways. Here too the process of delivery, and thus your right to initiate that process, derivatively involves some further control of my body. But this seems innocuous.

Second, and crucially, to say that one could own another’s kidney is not to say that the law should place no limits on the delivery rights of kidney purchasers. The right to alienate a kidney could be restricted to highly specific circumstances, such as when the surgery could be done safely, and perhaps only while we are in the same city. Strictly speaking, your purchase of the embedded kidney need not include the right to order immediate excision and delivery of the kidney without notice.[35] The situation might be different with hair, precisely because it is far more easily removed and delivered than a kidney. Perhaps the purchase of hair could indeed include the right to demand that I cut my hair and mail it to you immediately. The law invariably moulds ownership around the characteristics of the things it makes the subject of property rights, and body parts would not be unique in this respect.[36]

Let me offer a related clarification. Imagine you want to take your newly acquired kidney along on a bike ride. This is ordinarily within the rights of a chattel owner. Can you, therefore, order me to get on a bike? I don’t think so. If I am still wearing what is now your shirt, and you want the shirt to go on a bike ride, your right does not include the authority to order me onto a bike. You do have the right to ask that the shirt be put in your possession, and thus, you have the right to initiate the delivery process such that you (or your agent) can take the shirt on a bike ride. Something analogous goes for body parts. Buying my hair or my kidney does not furnish you with the right to order my entire person onto a bike (and much less so to forcibly take what is yours).

In closing this discussion of alienability, I want to acknowledge that something of note happens upon separation that implicates alienability. Separation from the body is likely to be a highly communicative act—one that signals that a body part is regarded by its source as property, and could potentially be for sale. For example, if I snip off my hair and hold it in my hands, others are more likely to think that I am willing to part with my hair. The ordinary state of affairs, where I simply walk around with my hair attached to my head, does not have this social resonance. As we saw in our discussion of possession, my property is not always physically contiguous with me. And so, holding my snipped-off hair in my hand suggests that the hair could be in someone else’s hands instead, which in turn evokes ideas of alienability, and thus ownability. In sum, there is a chain of social meaning linking separation, possession, alienability, and ownability. But none of this proves that I cannot own my hair until it is snipped off my head; this simply demonstrates why we (erroneously) tend to believe that separation is normatively significant.

C. Owners as Distinct from Their Property

Another closely related idea––and our next candidate rationale for the Separation Thesis—is that there must be a distinction (or metaphorically, a “separation”) between an owner and what she owns. As Penner helpfully explains: “If a relationship is a property relationship, there must be an owner and there must be something owned, and these two cannot be the same things.”[37] This thought warrants further development in the context of body parts. Penner makes this point in the midst of a discussion of slavery, so he is concerned about a wholesale rendering of the body as property. Because, by definition, that which is property can be owned by someone else, Penner is concerned about the dramatic case in which I have somehow sold the entirety of my body. This is indeed an impermissible concession of normative authority over my person, because, after all, we are embodied. If every part of my body is someone else’s, then there isn’t anything of me left over. This is another concern about slavery, but from a different angle than the one we saw above. Here the concern is that giving the “it-is-up-to-you”[38] power of property to someone else over the entirety of our bodies looks a lot like slavery (or just is slavery).

I think we can acknowledge Penner’s idea that there must be a difference between an owner and what they own, without also affirming that this two-part relationship cannot exist in the same human body. That is, Penner has presented us with the limiting case of the line between persons and property, where every square inch of my body is someone else’s. In such a case, it is indeed plausible that no person remains, and thus that there is no meaningful “separation” between my person and my property. But this does not show that, short of a total sale of my body parts to another, I cannot own some specific square inch of my body. One can remain an owner—that is, a person––while owning some of one’s attached body parts.[39] So, Penner’s claim about the distinction between owners and their property does not actually require a break in physical contiguity with the whole body for a body part to be ownable. Penner’s remark is best understood as a point about two distinctive normative relationships to our bodies, ownership and personhood, and how the former cannot entirely oust the latter in the same human body.[40]

D. Detachment and the Prospect of Reunification

A final argument for the Separation Thesis suggests that detached body parts undergo changes in their characteristics when they are detached. These changes ostensibly explain why a personal right morphs into a property right upon separation. Essert, following Japa Pallikkathayil, offers this argument for the sliced-off finger, writing that the finger “might be re-attached to me, and thus once again [becomes] part of the integral whole that is my person.”[41] For Essert, detached fingers and kidneys do not enter the realm of property, at least as long as they are reattachable. Essert sees a continuity in the source’s claim to fingers and kidneys because separation does not negate the possibility of reunification. But notably, hair falls on the other side of the ledger for Essert.[42] He writes that hair cutting is the creation of res, akin to the birth of a wild animal.[43] Accordingly, for Essert, if I gathered my detached hair to create a wig to put on my head, the wig would seem to be “mine” rather than a part of “me.”[44] This argument draws its plausibility from physical facts about the nature of the body parts in question: hair cannot be reattached in such a way that it forms a “part of the integral whole that is my person.”[45] Presumably this is because detached hair cannot grow again.[46] So, one virtue of this account is that it seems to avoid pointing to anything mysterious about the transition from attachment to detachment.[47]

An influential German case concerning stored sperm seems to have settled on a similar view.[48] Commentators, such as Niall Whitty, have endorsed the theory emerging from the case as “practical, coherent and morally satisfying.”[49] Whitty offers a helpful summary of the rules laid down by the case:

(i) A separated body part is, in law, a “thing” susceptible to ownership. On separation, the right of the person with respect to his or her own body is transformed into a right of property in the separated body part.

(ii) A body part destined to be returned to the original body and to perform its natural function thereafter (e.g. a bone-graft or skin-graft or an ovum after IVF) is not a thing susceptible to ownership. It is however protected by the person’s right of personality.

(iii) A body part permanently separated but destined to be united with another person’s body (e.g. donated blood or tissue) is also legally a thing susceptible to ownership.

(iv) Sperm stored in order to perform a function typical of the body––procreation––by the subject, but at the same time destined to be received by another’s body, is in the same position as an ovum after IVF mentioned in (ii) above. It is not a thing susceptible to ownership. The body forms a functional unit extending even to separated parts which are therefore also protected by the right of personality to the same extent as the body itself.[50]

The German court appears to suggest that sperm’s prospects for bodily reunification means that sperm is not res. This lends credence to the idea that separation is indeed morally transformative when it threatens the possibility of reunification, as it does for hair. Perhaps this provides a principled way of substantiating the Separation Thesis after all.

I want to note something curious about the German court’s view which will be helpful to my main response. Sperm was held to be protected by rights of personality even while outside the source’s body, because sperm was removed for the purpose of eventual unification with a body for the purposes of fertilization. But, of course, the person whose body is to receive the sperm is not the source of the sperm. So, it is not the prospect of reunification with my body that matters for my personal right, but rather the prospect of reunification with some body. In the ordinary course, sperm fulfilling its biological function in procreation involves sperm becoming part of another person. However, it is not obvious how this idiosyncrasy adjudicates between allocating a personal or property right. As the German court itself noted, donated blood is destined to be united with another person. Yet blood receives asymmetric treatment from the court; according to the German approach, blood destined for another’s body is my property, but sperm destined for another’s body is me.[51] So, separation vis-à-vis reunification is not doing the moral work here.

Now to my main response. Essert and Pallikkathayil (and German law) seem to regard the prospect of reattachment as morally weighty. On this view, hair’s inability to remain in a whole with our bodies once detached means that property is created, rather than a personal right preserved.[52] Kidneys and fingers are unlike this, as are prosthetics. This produces a curious asymmetry between Essert’s treatment of hair and prosthetics. Just like detached hair, a prosthetic arm will never be able to form a biological unity with its user. But Essert (rightly) suggests that a prosthetic is a part of my person, and remains this way when I put the prosthetic on my nightstand. So, when you interfere with my prosthetic while I am sleeping, you have battered me, (i.e., committed a personal, rather than proprietary, wrong).[53]

To be clear, Essert’s view is plausibly motivated by social considerations. In an egalitarian society, the law has strong normative reasons to regard a prosthetic or a wheelchair as a part of the person who uses them.[54] Though they are not part of their users’ natural bodies, the centrality of these objects in the lives of their users suggests they are part of their persons.[55] We should not adopt differential attitudes about those who use artificial rather than “real” limbs. Analogous concerns do not seem to arise for hair. We lose hair daily, mostly without noticing. Hair also grows back. I suspect that we bring these attitudes about the expendability of hair to our analysis of separation, rather than drawing any of these lessons from separation.[56] More broadly, social meanings associated with certain body parts and their artificial equivalents drive our analysis of separation, rather than a view about ontological change in the functional characteristics of those body parts due to separation. But if so, then biological unity is not what is doing the moral work (and nor should it).[57] As we saw with German law’s treatment of sperm, the “functionality” of a body part is itself socially determined and normatively charged. All of this suggests that we have no reason to take the prospect of reunification after separation (or the lack thereof) as the acid test for property in the body.

II. The Body as Me (And My Instrument)

Thus far, I have shown that separation from the body need not change (1) the fact of one’s normative control over a body part; or indeed (2) the kind of normative control one enjoys over a body part. I did this by dispelling four initially credible arguments aimed at substantiating the Separation Thesis. If the Separation Thesis is untenable and we can have property rights in detached body parts, then it is possible to have property rights in (some fraction of) our bodies. In this section, I argue that this is also normatively attractive and authentic to our pre-philosophical intuitions. I contend that less than the entirety of my body is me, and the rest is mine. The distinctive relationship of our persons to our bodies is best understood in terms of agency: we need our bodies to act in the world, and to be capable of developing and executing plans without dependence on other agents. And yet, we do not need the entirety of our bodies to achieve this.

Let’s work our way to this conclusion with an intuitive starting point. Embodiment has an important role in our being the persons we are and maintaining independence from other agents. We act through our bodies, so my control over my body is a precondition for acting in the world. This is what Pallikkathayil dubs the “body as means” view.[58] But, Pallikkathayil argues that this does not capture the unique relationship I have to my body. After all, I also need “air to breathe, food to eat and water to drink in order to function as [an agent].”[59] This motivates Pallikkathayil to dispense with the “body as means” view and instead endorse Arthur Ripstein’s view of the relationship between our persons and our bodies, according to which our bodies are, rather, us. Ripstein writes that “your person can never be physically separated from you” and that “your person is your body.”[60] This is what Pallikkathayil calls the “body as identity” view.[61] She adds, in support of the “body as identity” view, that the body has a unique role in constituting our separateness from other persons because “you need some kind of foothold in the world in order for the question of independence from other agents to even arise.”[62] The body is this foothold for Pallikkathayil.

All of this is relevant because Pallikkathayil suggests that this relationship between our persons and our bodies shows that nothing short of the totality of our bodies is the subject of our personhood. While she is willing to acknowledge indeterminacy in the outer limit of our persons––as between our bodies and the external world (when we use a wheelchair for example)––she resists what she calls the “radical” indeterminacy associated with identifying persons with something less than the totality of their bodies.[63] Pallikkathayil notes that the temptation of this radical view comes “from the thought that agency is possible with much less than your whole body.”[64] For example, I do not seem to need both of my kidneys to act as an agent.[65]

Yet Pallikkathayil rejects the “radical” view. As far as I can tell, she gives two distinct reasons for doing so. First, Pallikkathayil contends that identifying persons with less than the totality of their bodies would be to slip back into regarding the body as one of many possible instruments for embodied agency. The thought here is that we have begun to ask, “how much of this body do I really need to act as an agent anyway?” We thereby lose sight of my body’s distinctive relationship to my agency. Second, Pallikkathayil notes that even if we try to stay compliant with the “body as identity” view, when we try to determine what parts of my body are me, we will invariably reel in the whole body, as it were. Pallikkathayil puts this point as follows:

If we tried to identify you with your brain [for example], we would have in mind a living, active brain and that involves smuggling in the system in which that brain is operating. So, the answer to the question of identification cannot really be less than one’s whole body.[66]

I think both of these reasons for rejecting the possibility that I am less than the totality of my body are unsatisfying. First, Pallikkathayil is misguided in assuming that capturing the distinctive relationship of our persons to our bodies means we must adopt a non-instrumental understanding of the relationship of our bodies to our agency. It does seem that my body is instrumentally related to my agency; again, I must have a body to act as an agent. However, we can still retrieve the proposition that my body enjoys a unique or distinctive relationship to my agency while maintaining the “body as instrument” view.

To see these points, note that Pallikkathayil deems the “body as means” view inadequate because it does not ground the unique “sense in which some kind of control over one’s body is a precondition for independence.”[67] We saw Pallikkathayil argue that air, food, and water are just as necessary to our functioning as agents as our bodies. But these examples do not threaten the “body as instrument” view; in fact, they are just further requirements for having a fully functional body. The need for air, water, and food are all bodily requirements, though they are not a part of my body. So quite plausibly, these can all be subsumed under the banner of bodily rights, not because they are themselves part of my body, but because they are requirements for having a healthy, surviving, and functional body.[68] Moreover, the “body as instrument” view can capture the sense in which the body is uniquely relevant, albeit as an instrument, to agency. The other instruments we come to use in acting as agents—cars, planes, knives, forks, clothes, pens—will always be used through the prism of our bodies. These objects stand in more distant locations on the causal chain with my agency. Their use is mediated by my body.[69] All of this is compliant with the “body as instrument” view.

Pallikkathayil’s second argument has two premises: (1) capturing the distinctive relationship of my body to my independence as an agent requires endorsing the “body as identity” view; and (2) my independence as an agent requires that all of my body is my person. I think the first premise is false on the basis of what I suggested above, though I will cast more doubt on it below. I think the second premise is also dubious. Recall that we are in search of an account of the body’s role in our status as separate and independent agents. True, independence does require some notion of me as a person, distinct from you as a person. And so we must identify some portion of my body (including, possibly, all of it) as me rather than someone else. But it is not the case that I must have these fingers, this hair, or this kidney to be a separate person. I would be the same moral agent, capable of the same embodied activities, even if I received a kidney from my cousin, used a finger I bought from a stranger in Paris, and wore an abandoned wig of someone else’s hair I found in Seoul. While someone else (who is decidedly less of a Sorites paradox!) might have these body parts as part of their person, I might merely have them as things I own. This is perfectly consistent with the idea that they remain important for my agency, and my moral equality as a separate person. (I also might have less hair or one less kidney, and nonetheless remain the same person, distinct from other persons.) So while these body parts are useful to me, as my fork is, they are not a necessary site in the map of my identity. In part, this is because they are fungible—not in an economic sense, but in that they are interchangeable or even removable without violence to my separateness as a person. Thus, Pallikkathayil’s transition from the plausible proposition, “whatever part of the body we identify as me is part of a system of bodily unity,” to the conclusion, “therefore the whole body is me,” is a bit too hasty. Contra Pallikkathayil, agency and identity come apart in the body; they are not co-extensive.

I suspect that Pallikkathayil and others are resistant to the idea of my person being less than the totality of my body because they take a binary view of the issue: either some part of my body is me or I have no claim to that part of my body. This is implicit in Pallikkathayil’s argument that identifying the entire body with one’s person is the only way to resist the idea that the state can forcibly redistribute one’s organs while we are alive.[70] She writes that the situation changes when one dies, presumably because one’s person no longer exists. The state can legitimately maintain an opt-out program for organ donations from our corpses. As I suggested already, Pallikkathayil’s search for a unique relationship to our bodies is motivated by a “personhood-or-nothing” view of our right to our bodies; she does not explicitly consider the possibility that our right to our bodies could also be filled in by something else, such as property.[71] On the view that only my identity can ground a right to my body, when my person is shown to be something less than every nook and cranny of my body, my claim to the rest of my body looks mysterious.

As I have put the point before, the parts of my body that are not me are nonetheless mine. One allure of this view should be immediately apparent: while granting the plausible argument that the entirety of my body is not necessarily me, proprietary rights step in to ground my right to the remainder of my body.[72] And notice that the instrumental relationship of my body to my agency does not dilute the thought that my body is the most important instrument I use. As I said above, other, non-bodily instruments are used through my body. Insofar as embodiment remains an important part of being a separate agent, the parts of the body that secure this agency have a normative priority over those that do not.[73] This is also why my right to (much of) my body is more fundamental than my right to my oft-used fork.[74]

However, notice that certain parts of my body are indeed akin to my fork. We regard a not-insignificant fraction of our bodies as we do our forks. That is, I can lose my fork and use another, or indeed stop using forks entirely. Similarly, I can lose my hair or constantly cut it off to sell wigs, and yet remain a separate agent. (Indeed, commercial wig production using human hair is a venerable practice, at least as old as the Egyptians.)[75] Similarly, I can extract one of my kidneys without comprising my bodily integrity and remain capable of self-directed motion. Such body parts invite treatment as property.

To sum up these rather abstract arguments, I think that the body matters for personhood, as Pallikkathayil urges. But, as it happens, the biological unity required for agency implicates something less than the whole of the natural body. This conclusion is consistent with the view that the physical unit that contains our identity as embodied persons has deep (and perhaps unique) moral significance.[76] It just turns out that the physical integrity that is constitutive of one’s independence as an agent is not the totality of one’s body.

This position also provides a framework within which to answer questions like: “How do I know my hair, but not my brain, is mine and not a part of me?” My suggestion is that those body parts implicated in my separateness as an agent are me, but that the remainder of the body is mine. Categorizing some specific body parts will be difficult, as categorizing particulars always is. But, importantly, this reorientation means that we will approach the task of categorizing particulars with the right question in mind. It is not the act of separation from our biological bodies that is of significance. Rather, it is our moral and political commitments about personhood that should guide us in determining whether some particular body part is a part of our persons or merely something that we own. This method is unabashedly normative. Rather than policing a morally arbitrary distinction between attached and unattached body parts, we will acknowledge that what counts as crucial to our agency is a normative question––albeit the right normative question.

More pointedly, this position also wards off a moral misstep made by the prevailing, no-property-in-the body orthodoxy.[77] We risk endorsing a kind of biological parochialism by insisting that the entire natural body, and nothing else, constitutes our person. On the view that my person and my body are co-extensive, a wheelchair must be confined to the domain of property, while all of my body, including those parts I part with regularly, such as my hair and nails, are part of my person. The line between these categories is not written in the metaphysical fabric of the world. We can carve the distinction between personhood and property in our bodies normatively, just as we should do with objects in the “external” world. Accordingly, one feature of my view is that it allows us to recognize the importance of embodiment, but discard the biological parochialism. Where prosthetics, wheelchairs, and other non-biological things take up agency functions, in that they fulfill the (bodily) functions necessary for my being an independent agent, they are plausibly assimilated into my person. This allows us to explain why, despite not being biological, such objects can nonetheless become a part of me. There is a stencil of personhood required for agency, and this stencil can be filled by both biological and artificial body parts.

Moreover, the view I offer here is an important corrective to the idea that there is something grotesque about allowing for property rights in body parts because the biological body is sacrosanct. This idea has exerted a powerful grip on thinking about property rights and body parts generally, and the commodification literature in particular. Such worries are at least as old as Ronald Dworkin’s remark that we should maintain “a prophylactic line that comes close to making the body inviolate, that is, making body parts not part of social resources at all.”[78] We can make Dworkin’s concern a bit more concrete. For example, many would abhor the idea of allowing people––particularly disadvantaged people––to pledge their body parts as collateral for a bank loan, as property treatment appears to invite.[79]

I think this concern is misguided in two ways. First, the idea that we should draw a prophylactic line around the body is both overinclusive and underinclusive. It is overinclusive because, as I have suggested, less than the totality of the biological body is a precondition for the personhood that Dworkin seeks to insulate from the whims of redistribution and market forces. Moreover, it is underinclusive, as many non-bodily objects can take up key personhood functions. First, to draw the line at the biological body alone is to exclude such objects, and fall into the biological parochialism described above. Second, if surrendering body parts to pay off one’s creditors in bankruptcy proceedings is best prohibited, the law should hold the line at the level of bankruptcy law, rather than generally denying that body parts are ownable.[80] There may be a host of compelling policy reasons to insulate body parts from forfeiture and bankruptcy proceedings.[81] But the key point is that the body is far from unique in attracting such concerns. A Hindu made to involuntarily surrender her ancestral idol in order to satisfy a legal claim––thereby losing the object of her daily worship––will feel a loss at least equal to the loss of a body part.[82] Yet such objects are not beyond the pale of ownership simply by virtue of being intimately connected with the personhood of their owners. The same is true of body parts.

The disadvantaged are routinely separated from or deprived of property. Inequality is a relational, formal problem about some people having property and others having less (or none). However, property-based inequality is not primarily an issue about what particular kinds of property the disadvantaged rather than the advantaged have (though it is, of course, important that we all have real property rights of some kind to ward off the relational inequality inherent in homelessness).[83] Our concern with economic exploitation is with relational subordination, not the peculiar objects of property that the poor are deprived of, about which we may have culturally-contingent attitudes.[84]

III. Private Law, Private Wrongs, and the Body

Thus far I have tried to assemble a normatively attractive account of the relationship of our persons to our bodies. I argued that such an account does not require resisting the idea of property in the body; on the contrary, it recommends that idea. In doing this, I have been speaking only obliquely about private law’s role in these subjects. I now want to show that the law can rely on the view I have assembled to countenance the personal and proprietary wrongs one commits when a body part is excised from another without their consent. My view is explanatorily and remedially satisfying.

Let me preface this with a few familiar reflections on what is at stake in the distinction between personal and proprietary rights. As forms of normative authority, these rights differ at a legal-philosophical level because they secure different kinds of freedom in correspondingly different ways. Personal rights are important to secure our independence from other persons, and they do this by shielding that interest from alienability.[85] That is, my person must always be mine lest I become someone else’s slave. Property is different, and is perhaps a mirror image of personal rights, because I can lend, share, gift, or sell my property (among other things). The freedom secured by property is secured by alienability. When we drop down to legal doctrine, we see structural differences between wrongs to persons and wrongs to property. A battery is a “trespass to the person.”[86] By contrast, to interfere with my property is to interfere with something I have, not me. So apart from philosophical interest, understanding the kind of rights we have in our bodies is key to understanding the relevant wrongs, and in turn the remedies the law furnishes, when our bodies are interfered with.

This in mind, I want to make the case for the explanatory power of my account by way of an example. Suppose you creep up behind me and snip the hair off my head without my consent.[87] I am imagining a version of this example in which you hold my hair and then snip (as a barber might). First, notice that supposing my hair is mine, rather than me, is not a barrier to my launching a claim in battery. When you touch my shirt without touching my body, this is still a battery.[88] Analogously, when you touch my hair, the fact that my hair is in physical contiguity with the rest of my person means that this is still a battery. So my account does not sacrifice access to the tort of battery in virtue of finding property in the body. But, to return to the main thread, notice that when you snip my hair off my head, you also take my body part away from me. You leave with something that I now correspondingly lack. My account vindicates this intuition in a satisfying way, unlike proponents of the view that there is no property in the body. On the view that the hair on my head is mine, you are also liable in conversion––a proprietary wrong. All of this is consonant with the moral reality of the situation, which consists in a plurality of wrongs.[89] You have both done something to me and taken something that is mine.

Essert––whom I have conscripted as the spokesperson for the prevailing no-property-in-the-body orthodoxy––may insist that his account can also explain the plurality of wrongs that occurs in the hair-snipping case. That is, Essert holds that you batter me when you snip my hair off my head, but that this happens to be a peculiar battery such that the hair becomes res upon separation. Essert might add that there are strong reasons to suppose that, as a default norm of acquisition, the biological source is the owner of the newly ownable, severed hair. On this view, too, when you run away with my hair after snipping it off, I have a claim in both battery and conversion. In this way, Essert’s view can reach the same result as the view I have offered.

However, I think Essert’s explanation is less appealing. There is something normatively undesirable about the idea that the same act that we in one breath call a battery, should be what ushers in the transition to a property right (even if that property right is said to vest in the source by default). Notice that in conceptualizing the wrongs that occur during the snipping incident, Essert’s view––and any view committed to the Separation Thesis in some form––allows the tortfeasor to unilaterally, by her act, change the status of my right to a part of my body. One might respond that this is not particularly troubling, because the law will suffer a tortfeasor doing something analogous in other contexts. For example, if you break my irreplaceable and irreparable statue into two, I now own two pieces of property rather than one. As a tortfeasor, you have created an “extra” property right.

But I think this situation is different for two reasons. First, there is no change in the kind of right I hold in the statue. It is still property that I am left with. By contrast, in the snipping incident, the nature of the right is being changed—and arguably, demoted—from a personal to a proprietary right.[90] This is the kind of transition that the right-holder should decide. This principle is authentic to the Weinribian idea of symmetry between right and remedy, and the normative continuity of the right despite its violation.[91] Your taking my hair is the reason I am owed a proprietary remedy. The alternative explanation––that you battered me, and just happened to create property in the process––lacks the continuity between right and remedy, though it claws its way to the same result.[92]

Second, in the case of the bisected statue, the law cannot ignore the empirical reality that two distinct things have been created. In fact, to do so would be to lose sight of the peculiar wrong that occurs when you break my statue into two.[93] In the hair-snipping incident, by contrast, the empirical reality can sustain two different normative interpretations. Either my hair has been converted from me to mine or the hair simply remains mine. As we saw above, separation underdetermines the choice between the continuity of a right and its transformation. So the explanation generated by my account is the preferable one; it explains the moral wrongs for the right reasons, and does so without commitment to any normatively undesirable upshot.

For the sake of offering a complete picture, I want to make one final observation about the taxonomy of bodily wrongs. Again, let me do so by way of an example. Suppose you yank my hair while it is on my head, but do not succeed in ripping it off. More generally, this raises the issue of what view private law should take when you yank (or pull or twist) my bodily property without inducing separation. No doubt you are liable in battery, as we have seen above. The interesting question is whether there is additionally a conversion here, as there was when you cut off my hair and ran away with it. Conversion is a difficult tort to characterize and distinguish from its conceptual and historical property-tort cousins. Recent work by Simon Douglas suggests that conversion concerns the intentional exercise of exclusive control over another’s chattel, as if the chattel were one’s own.[94] The tortfeasor need not derive a benefit from an impermissible exercise of control or take possession of the chattel.[95] So perhaps you are liable in conversion in virtue of the hair yank, just as you would be if you yanked on a shirt I was wearing. However, I think the main obstacle to regarding both these yanks as conversions is the “exclusivity” requirement, viz., that at some point, the defendant was the only person controlling the chattel.[96] This is where conversion gets its “property-wrongness”: the tortfeasor excludes the owner as if she herself owned the chattel. In both examples, it’s not clear that I have ever been deprived of control of my chattels, because they still remain on my person in both cases. To analogize to another example, if you try to wrest an apple that I own out of my grip without touching my hand, you batter me because you thereby force my hand to move without my consent.[97] However, I am inclined to say that there is no conversion if you do not succeed in removing my apple from my hand, because there is no moment where you are in exclusive (factual) control of the apple. In fact, the situation is best characterized as a struggle for such control. Something analogous, I think, goes for the situation in which you yank my hair. You are not liable in conversion, unlike when you snip off my hair and thereby take exclusive control of it when the hair falls into your hands.[98]

IV. Rejecting the Jurisprudence of the Separation Thesis

In addition to offering a satisfying conceptual taxonomy of bodily wrongs, my account also offers a principled way forward in the face of scattered doctrinal developments concerning separated biomaterials. A series of well-known cases takes the following form: S undergoes some medical procedure, during which T excises some body part or bodily tissue from S’s body.[99] Without S’s authorization, T subsequently makes some use of the body parts (e.g., for lucrative scientific research) or damages them somehow. Such disputes have served as occasions for courts to pronounce on whether S has property in their body parts. The resulting answers are mixed, and the doctrine is beset by a series of difficulties.[100]

Moore v. Regents of the University of California is perhaps the best-known case of this kind. John Moore was a patient at the University of California Los Angeles (UCLA) Medical Center, and had samples of his blood, sperm, and other bodily tissue extracted for the purposes of diagnosing his hairy-cell leukemia.[101] Moore came to see Dr. David W. Golde at UCLA because Dr. Golde was one of a handful of physicians in the world who was then conducting research on this distinctive cancer. The periodical sampling of bodily tissue was part of the routine monitoring of the patient by the treating oncologist. But unbeknownst to Moore, the physicians at the UCLA Medical Center, including Dr. Golde, took a special, non-therapeutic interest in Moore’s body parts. Dr. Golde quickly realized that Moore’s genetic material could be used for important scientific research. He conducted gratuitous excisions of Moore’s tissue to establish a cell line from Moore’s T-lymphocytes, representing these procedures to Moore as medically necessary.[102] Eventually, Dr. Golde registered a patent in the cell line along with another co-inventor.[103] Moore sued.

While giving effect to Moore’s claims for breach of fiduciary duty, the Supreme Court of California held that Moore lacked the requisite property interest in the cells needed for a conversion action. Yet the court was prepared to hold that Dr. Golde had acquired a property right, arguing that he had done the work of converting mere biological material into the “factually and legally distinct” patented cell line.[104] This troubling asymmetry is difficult to justify. Why should the source be barred from a property right while a third party tortfeasor has access to such a right?[105] The asymmetry in Moore gets its impetus from a prior commitment to the Separation Thesis.

One might attempt to substantiate the asymmetry by arguing that Dr. Golde effectively created something “new.” As we saw just a moment ago, the majority in Moore made a version of this argument. The court held that the patented cell line was both “factually and legally distinct” from Mr. Moore’s bodily tissues, because Dr. Golde had, by his efforts, converted (excuse the pun!) Moore’s cells to a patentable cell line, an arduous and intellectually-charged task.[106] After all, Moore cannot have had a patent in his own unmodified cells,[107] any more than I can have a patent in a fistful of dirt that I gather up in my garden.

This rejoinder misses the mark. My contention is not that the asymmetry between Dr. Golde’s patent––a creature of statute––and Moore’s lack of a patent is impossible to justify. That asymmetry may, in toto, be defensible, precisely because merely “naturally-occurring” substances, such as Moore’s cells, cannot be the subject of a patent. The asymmetry I am pointing to is a more general one, namely the asymmetry between the fact that Dr. Golde walked away with a property right, while Moore, simply in virtue of being unfortunate enough to be the biological source of the cells, was found to have no property right, and thus no proprietary remedy. Whether a patented cell line is qualitatively distinct from “mere” cell tissue is a distinct issue. My argument does not turn on the truth or falsity of that proposition.

One might contend that it was not separation, but some later event after separation that transformed Moore’s cells into Dr. Golde’s property, namely, Golde’s work in altering the cells into a cell line. This looks like a way of reaching the Moore court’s result without endorsing the Separation Thesis. However, this reimagined justification also fails. Ex hypothesi, if this objection is not committed to the Separation Thesis, Moore must have owned his tissue right until the moment it was converted into something new––cell lines––by Dr. Moore. The ancient Roman doctrine of accession, received into American common law, provides that a new thing made from the property of another that is of a “different species” than the original constituents becomes the property of the labourer, as long as compensation is provided for the value of the original constituents.[108] However, this doctrine is only available where the improver is innocent and has not acted in bad faith.[109] Dr. Golde would not have been entitled to invoke the doctrine to ground his right in the cell lines even if he had indeed fashioned something new from Moore’s cells. Dr. Golde had breached his fiduciary duties, after all.

The Moore court’s effort to deny Moore a remedy was premised on the erroneous assumption that whatever property right existed could only have come into existence after separation from Moore’s body. The majority weaponized this assumption to find that only the patented cell line “existed” after separation. If we acknowledge that Moore had a property right before separation, we can in turn see that Dr. Golde’s property right did not pop into existence from thin air, as if Dr. Golde had somehow worked upon a freshly landed meteor from space. Dr. Golde’s cell line was a descendant of Moore’s cells, and thus, any purported property right held by Dr. Golde had to be traced to Moore’s extant property right. In other words, Dr. Golde did not convert some res nullius into his res; he purported to seize Moore’s res by his own efforts. That, he could not have done. Jettisoning the Separation Thesis sharply crystallizes the issue in Moore.

Consider another difficulty with the prevailing orthodoxy. If we cling on to the Separation Thesis in supposing that separation creates something ownable, as the law presently does, it does not immediately follow that I own my body part when that body part becomes detached. To repurpose an example from the previous section, it is not obvious that I own my hair when my hair is snipped off by you.[110] In the ordinary course, first possession is the norm of acquisition that applies to something that was once res nullius, and is now entering the world of property for the first time.[111] But this looks morally arbitrary, if not downright unjust, in the case in which you are the one who has snipped off my hair without my consent, and thereby come to possess it. In the face of this, we might appeal to a sui generis norm of acquisition for body parts, one that gives priority to the biological source. Yet even this suggestion is not free from controversy. Echoing the ideas that carried the day in Moore, courts and commentators have suggested that those who have “created” a “new thing” by extracting a body part—such as a doctor taking a blood sample or removing tissue––should thereby have title to that body part.[112]

On my account, we avoid having to determine whether a personal right continues uninterrupted despite separation, or if the right is transformed to property because of separation. If property in particular body parts exists prior to separation, then we know (1) if someone owns a body part after separation; and indeed (2) who owns that body part. There is no need to resort to norms of acquisition––and to partake in the controversy this invites––because my view renounces any metaphysical commitments concerning separation. And this best accords with the intuitive position—the source does not acquire anything upon separation. The source simply maintains something that was theirs all along.

There are disparate social meanings, as well as differing biological and functional capabilities that accompany the separation of different body parts. Thus, even having a blanket property-creation rule for all separated body parts would achieve clarity only by regularly working contrary to the reasonable expectations of legal subjects.[113] As we saw in our discussion of German law, it is not obvious whether sperm should get personal or proprietary treatment when removed from the body.

The decision of the England and Wales Court of Appeal in Yearworth v. North Bristol NHS Trust is plagued by similar issues, despite reaching a different conclusion than Moore.[114] The Yearworth court also endorsed the Separation Thesis. As in Moore, the Yearworth court awarded the plaintiffs a remedy, but failed to award the remedy that best vindicated the plaintiffs’ claims. The plaintiffs were a number of men who were diagnosed with cancer and wished to protect their sperm from the punishing side effects of chemotherapy.[115] On the suggestion of doctors, the men agreed to deposit their sperm in a storage facility.[116] Sometime later, a mishap in the storage facility’s temperature controls resulted in their sperm being permanently damaged and rendered the sperm unsuitable for reproductive purposes. Unlike in Moore, the plaintiffs couched their actions in negligence for psychiatric injury and mental distress (i.e., personal, rather than proprietary, wrongs). Only in the alternative did they contend that their property rights were infringed. Counsel for the plaintiffs argued that the mere fact of ejaculation should not make a difference to the availability of a finding of personal injury, as would have been the finding had the sperm been damaged while still in the scrotum.

The court acknowledged that the plaintiffs’ position aligned with German law’s approach to detached sperm.[117] Despite this, the court held that “it would be a fiction to hold that damage to a substance generated by a person’s body, inflicted after its removal for storage purposes, constituted a bodily or ‘personal injury’ to him.”[118] The court was not explicit about exactly what it found fictional about the German position, but it appears that the court thought that one’s person was co-extensive with only one’s attached body parts.[119] The court instead held that the men had property in their sperm, which in turn allowed them to claim negligence damages.[120]

Yet, despite awarding the men a remedy, the court failed to redress the distinctive wrongs the men were alleging, which sounded in personal, rather than proprietary, terms. As we have seen, there are a host of reasons to suppose that separation does not invariably transform personal rights to property rights. The plaintiffs’ argument, that they retained personal rights over the sperm despite separation, went essentially unanswered by the court, which is in turn a symptom of the court’s inability to escape the Separation Thesis. I see no principled reason for the law to continue to assign such importance to separation from the body and the res nullius rule, particularly in light of the doctrinal difficulties that hound this commitment, and the rewards that come with rejecting it.


Where does this leave us? It remains true that our relationship to our persons differs in important ways from our relationship to our property. On an intuitive picture, my person is my body, and the outside world is merely the realm of the things that I can own. Yet there are problems with this picture. For one, some have persuasively argued that my right to my person can stretch beyond my body, and into the world. I have argued for a kind of symmetry: the frontier between our persons and our property is reproduced at a second locus, namely, within our bodies. While some of my body is me, parts of my body can also be mine.

These are perhaps startling results. I have suggested that our legal persons are both more and less than our bodies; things can become parts of our persons, and parts of our bodies can be our things. Yet this is just what it is to be embodied free beings living in a spatial reality populated by persons and things, and overlaid by law. The law can make these categories porous, and we can use the law to traverse their borders.