 property, rights and liberty. Libertarians tend to agree on a wide array of policies and principles. Nonetheless, it is not easy to find consensus on what libertarianism's defining characteristic is, or on what distinguishes it from other political theories and systems. Various formulations abound. It is said that libertarianism is about individual rights, property rights, the free market, capitalism, justice or the non-aggression principle. Not just any of these will do, however. Capitalism and the free market describe the catalactic conditions that arise or are permitted in a libertarian society, but do not encompass other aspects of libertarianism. And individual rights, justice and aggression collapse into property rights. As Murray Rothbard explained, individual rights are property rights, and justice is just giving someone his due, which depends on what his rights are. The non-aggression principle is also dependent on property rights, since what aggression is depends on what our property rights are. If you hit me, it is aggression because I have a property right in my body. If I take from you the apple you possess, this is trespass, aggression, only because you own the apple. One cannot identify an act of aggression without implicitly assigning a corresponding property right to the victim. So capitalism and the free market are too narrow, and justice, individual rights and aggression all boil down to or are defined in terms of property rights. What of property rights then? Is this what differentiates libertarianism from other political philosophies? That we favour property rights and all others do not? Surely such a claim is untenable. After all, a property right is simply the exclusive right to control a scarce resource. Property rights specify which persons own, that is, have the right to control, various scarce resources in a given region or jurisdiction. Yet everyone and every political theory advanced some theory of property. None of the various forms of socialism deny property rights. Each version will specify an owner for every scarce resource. If the state nationalises an industry, it is asserting ownership of these means of production. If the state taxes you, it is implicitly asserting ownership of the funds taken. If my land is transferred to a private developer by eminent domain statutes, the developer is now the owner. If the law allows a recipient of racial discrimination to sue his employer for a sum of money, he is the owner of the money. Protection of and respect for property rights is thus not unique to libertarianism. What is distinctive about libertarianism is its particular property assignment rules, its view concerning who is the owner of each contestable resource and how to determine this. Property in Bodies A system of property rights assigns a particular owner to every scarce resource. These resources obviously include natural resources such as land, fruits of trees and so on. Objects found in nature are not the only scarce resources, however. Each human actor has, controls and is identified and associated with a unique human body, which is also a scarce resource. Both human bodies and non-human scarce resources are desired for use as means by actors in the pursuit of various goals. Accordingly, any political theory or system must assign ownership rights in human bodies as well as in external things. Let us consider first the libertarian property assignment rules with respect to human bodies and the corresponding notion of aggression as it pertains to bodies. Libertarians often vigorously assert the non-aggression principle. As Ein Rand said, so long as men desire to live together, no man may initiate. Do you hear me? No man may start. The use of physical force against others. Or as Rothbard put it, the libertarian creed rests upon one central axiom, that no man or group of men may aggress against the personal property of anyone else. This may be called the non-aggression axiom. Aggression is defined as the initiation of the use or threat of physical violence against the person or property of anyone else. Aggression is therefore synonymous with invasion. In other words, libertarians maintain that the only way to violate rights is by initiating force, that is by committing aggression. Libertarianism also holds that, while the initiation of force against another person's body is impermissible, force used in response to aggression, such as defensive, restitutive, or retaliatory or punitive force, is justified. Now in the case of the body it is clear what aggression is, invading the borders of someone's body, commonly called battery, or more generally, using the body of another without his or her consent. The very notion of interpersonal aggression presupposes property rights in bodies, more particularly that each person is, at least prima facie, the owner of his body. Non-libertarian political philosophies have a different view. Each person has some limited rights in his own body, but not complete or exclusive rights. Society, or the state purporting to be society's agent, has certain rights in each citizen's body too. This partial slavery is implicit in state actions and laws, such as taxation, conscription and drug prohibitions. The libertarian says that each person is the full owner of his body. He has the right to control his body, to decide whether or not he ingests narcotics, joins an army, and so on. Those various non-libertarians who endorse any such state prohibitions, however, necessarily maintain that the state, or society, is at least a partial owner in the body of those subject to such laws, or even a complete owner in the case of conscriptees or non-aggressive criminals incarcerated for life. Libertarians believe in self-ownership. Non-libertarians, statists of all stripes advocate some form of slavery. Self-ownership and conflict avoidance. Without property rights, there is always the possibility of conflict over contestable, scarce resources. By assigning an owner to each resource, legal systems make possible conflict-free use of resources by establishing visible boundaries that non-owners can avoid. Libertarianism does not endorse just any property assignment rule, however. It favours self-ownership over other ownership, slavery. The libertarian seeks property assignment rules because he values or accepts various ground norms, such as justice, peace, prosperity, cooperation, conflict avoidance and civilisation. The libertarian view is that self-ownership is the only property assignment rule compatible with these ground norms. It is implied by them. As Professor Hopper has shown, the assignment of ownership to a given resource must not be random, arbitrary, particularistic or biased if it is actually to be a property norm that can serve the function of conflict avoidance. Property title has to be assigned to one of the competing claimants based on the existence of an objective, intersubjectively ascertainable link between the owner and the resource claimed. In the case of one's own body, it is the unique relationship between a person and his body, his direct and immediate control over his body and the fact that at least in some sense a body is a given person and vice versa, that constitutes the objective link sufficient to give that person a claim to his body superior to typical third-party claimants. Moreover, any outsider who claims another's body cannot deny this objective link in its special status, since the outsider also necessarily presupposes this in his own case. This is so because in seeking dominion over the other and in asserting ownership over the other's body, he has to presuppose his own ownership of his body. In so doing, the outsider demonstrates that he does place a certain significance on this link, even as at the same time he disregards the significance of the other's link to his own body. Libertarianism recognises that only the self-ownership rule is universalisable and compatible with the goals of peace, cooperation and conflict avoidance. We recognise that each person is prima facie, the owner of his own body, because by virtue of his unique link to and connection with his own body, his direct and immediate control over it, he has a better claim to it than anyone else. Libertarians apply similar reasoning in the case of other scarce resources, namely external objects in the world that, unlike bodies, were at one point unowned. In the case of bodies, the idea of aggression being impermissible immediately implies self-ownership. In the case of external objects, however, we must identify who the owner is before we can determine what constitutes aggression. As in the case with bodies, humans need to be able to use external objects as means to achieve various ends. Because these things are scarce, there is also the potential for conflict. And, as in the case with bodies, Libertarians favour assigning property rights so as to permit the peaceful, conflict-free productive use of such resources. Thus, as in the case with bodies, property is assigned to the person with the best claim or link to a given scarce resource, with the best claim standard based on the goals of permitting peaceful, conflict-free human interaction and use of resources. Unlike human bodies, however, external objects are not part of one's identity, are not directly controlled by one's will, and significantly, they are initially unowned. Here, the Libertarian realises that the relevant objective link is appropriation, the transformation or imbordering of a previously unowned resource, Lockean homesteading, the first use or possession of the thing. Under this approach, the first prior user of a previously unowned thing has a prima facie better claim than a second later claimant, solely by virtue of his being earlier. Why is the appropriation the relevant link for determination of ownership? First, keep in mind that the question with respect to such scarce resources is who is the resource's owner? Recall that ownership is the right to control, use or possess. While possession is actual control, the factual authority that a person exercises over a corporeal thing. The question is not who has physical possession, it is who has ownership. Thus, asking who is the owner of a resource presupposes a distinction between ownership and possession, between the right to control and actual control. And the answer has to take into account the nature of previously unowned things, namely that they must at some point become owned by a first owner. The answer must also take into account the presupposed goals of those seeking this answer, rules that permit conflict-free use of resources. For this reason, the answer cannot be whoever has the resource or whoever is able to take it is its owner. To hold such a view is to adopt a might-makes-right system where ownership collapses into possession for want of a distinction. Such a system, far from avoiding conflict, makes conflict inevitable. Instead of a might-makes-right approach, from the insight noted above it is obvious that ownership presupposes the prior-later distinction. Whoever any given system specifies as the owner of a resource, he has a better claim than latecomers. If he does not, then he is not an owner, but merely the current user or possessor. If he is supposed an owner on the might-makes-right principle in which there is no such thing as ownership, it contradicts the presuppositions of the inquiry itself. If the first owner does not have a better claim than latecomers, then he is not an owner, but merely a possessor and there is no such thing as ownership. More generally, latecomers' claims are inferior to those of prior possessors or claimants who either homesteaded the resource or who can trace their title back to the homesteader or earlier owner. The crucial importance of the prior-later distinction to libertarian theory is why Professor Hopper repeatedly emphasises it in his writing. Thus, the libertarian position on property rights is that in order to permit conflict-free productive use of scarce resources, property titles to particular resources are assigned to particular owners. As noted above, however, the title assignment must not be random, arbitrary or particularistic. Instead, it has to be assigned based on the existence of an objective, intersubjectively ascertainable link between owner and the resource claimed. As can be seen from the considerations presented above, the link is the physical transformation or in bordering of the original homesteader or a chain of title traceable by contract back to him. Consistency and Principle Not only libertarians are civilised, most people give some weight to some of the above considerations. In their eyes, a person is the owner of his own body, usually. A homesteader owns the resource he appropriates unless the state takes it from him by operation of law. This is the principal distinction between libertarians and non-libertarians. Libertarians are consistently opposed to aggression, defined in terms of invasion of property borders where property rights are understood to be assigned on the basis of self-ownership in the case of bodies and in the case of other things, rights are understood on the basis of prior possession or homesteading and contractual transfer of title. This framework for rights is motivated by the libertarians' consistent and principled valuing of peaceful interaction and cooperation in short of civilised behaviour. A parallel to the Missy Zayn view of human action may be illuminating here. According to Mises, human action is aimed at alleviating some felt uneasiness. Thus, means are employed, according to the actor's understanding of causal laws, to achieve various ends, ultimately the removal of uneasiness. Civilised man feels uneasy at the prospect of violent struggles with others. On the one hand he wants, for some practical reason, to control a given scarce resource and to use violence against another person if necessary to achieve this control. On the other hand, he also wants to avoid a wrongful use of force. Civilised man, for some reason, feels reluctance, uneasiness at the prospect of violent interaction with his fellow man. Perhaps he has reluctance to violently clash with others over certain objects because he has empathy with them. Perhaps the instinct to cooperate is a result of social evolution. As Mises noted, there are people whose only aim is to improve the condition of their own ego. There are other people with whom awareness of the troubles of their fellow men causes as much uneasiness as or even more uneasiness than their own wants. Whatever the reason, because of this uneasiness when there is the potential for violent conflict, the civilised man seeks justification for the forceful control of a scarce resource that he desires but which some other person opposes. Empathy, or whatever spurs man to adopt the libertarian grunt norms, gives rise to a certain form of uneasiness which gives rise to ethical action. Civilised man may be defined as he who seeks justification for the use of interpersonal violence. When the inevitable need to engage in violence arises for defence of life or property, civilised man seeks justification. Naturally, since this justification seeking is done by people who are inclined to reason and peace, justification is after all a peaceful activity that necessarily takes place during discourse. What they seek are rules that are fair, potentially acceptable to all, grounded in the nature of things and universalisable, and which permit conflict free use of resources. Libertarian property rights principles emerge as the only candidate that satisfies these criteria. Thus, if civilised man is he who seeks justification for the use of violence, the libertarian is he who is serious about this endeavour. He has a deep, principled, innate opposition to violence and an equally deep commitment to peace and cooperation. For the foregoing reasons, libertarianism may be said to be the political philosophy that consistently favours social rules aimed at promoting peace, prosperity and cooperation. It recognises that the only rules that satisfy the civilised grand norms are the self-ownership principle and the Lockean homesteading principle applied as consistently as possible. And as I have argued elsewhere, because the state necessarily commits aggression, the consistent libertarian in opposing aggression is also an anarchist.