"...outside the Garden of Eden, in the realm of scarcity, there must be rules that regulate not only the use of personal bodies but also of everything scarce so that all possible conflicts can be ruled out. This is the problem of social order.
II The Solution: Private Property and Original Appropriation
In the history of social and political thought, various proposals have been advanced as a solution to the problem of social order, and this variety of mutually inconsistent proposals has contributed to the fact that today’s search for a single “correct” solution is frequently deemed illusory. Yet as I will try to demonstrate, a correct solution exists; hence, there is no reason to succumb to moral relativism. The solution has been known for hundreds of years, if not for much longer.  In modern times this old and simple solution was formulated most clearly and convincingly by Murray N. Rothbard. 
Everyone is the proper owner of his own physical body as well as of all places and nature-given goods that he occupies and puts to use by means of his body, provided that no one else has already occupied or used the same places and goods before him. This ownership of “originally appropriated” places and goods by a person implies his right to use and transform these places and goods in any way he sees fit, provided that he does not thereby forcibly change the physical integrity of places and goods originally appropriated by another person. In particular, once a place or good has been first appropriated, in John Locke’s words, by “mixing one’s labor” with it, ownership in such places and goods can be acquired only by means of a voluntary – contractual – transfer of its property title from a previous to a later owner.
In light of widespread moral relativism, it is worth pointing out that this idea of original appropriation and private property as a solution to the problem of social order is in complete accordance with our moral “intuition.”
Is it not simply absurd to claim that a person should not be the proper owner of his body and the places and goods that he originally, i.e., prior to anyone else, appropriates, uses and/or produces by means of his body? For who else, if not he, should be their owner? And is it not also obvious that the overwhelming majority of people – including children and primitives – in fact act according to these rules, and do so as a matter of course?
Moral intuition, as important as it is, is not proof. However, there also exists proof of the veracity of our moral intuition.
The proof is twofold.
On the one hand, the consequences that follow if one were to deny the validity of the institution of original appropriation and private property are spelled out: If person A were not the owner of his own body and the places and goods originally appropriated and/or produced with this body as well as of the goods voluntarily (contractually) acquired from another previous owner, then only two alternatives would exist. Either another person, B, must be recognized as the owner of A’s body as well as the places and goods appropriated, produced or acquired by A, or both persons, A and B, must be considered equal co-owners of all bodies, places and goods.
In the first case, A would be reduced to the rank of B’s slave and object of exploitation. B would be the owner of A’s body and all places and goods appropriated, produced and acquired by A, but A in turn would not be the owner of B’s body and the places and goods appropriated, produced and acquired by B. Hence, under this ruling two categorically distinct classes of persons would be constituted – Untermenschen such as A and Übermenschen such as B – to whom different “laws” apply. Accordingly, such ruling must be discarded as a human ethic equally applicable to everyone qua human being (rational animal). From the very outset, any such ruling is recognized as not universally acceptable and thus cannot claim to represent law. For a rule to aspire to the rank of a law – a just rule – it is necessary that such a rule apply equally and universally to everyone.
Alternatively, in the second case of universal and equal co-ownership, the requirement of equal law for everyone would be fulfilled. However, this alternative would suffer from an even more severe deficiency, because if it were applied, all of mankind would instantly perish. (Since every human ethic must permit the survival of mankind, this alternative must also be rejected.) Every action of a person requires the use of some scarce means (at least of the person’s body and its standing room), but if all goods were co-owned by everyone, then no one, at no time and no place, would be allowed to do anything unless he had previously secured every other co-owner’s consent to do so. Yet how could anyone grant such consent were he not the exclusive owner of his own body (including his vocal chords) by which means his consent must be expressed? Indeed, he would first need another’s consent in order to be allowed to express his own, but these others could not give their consent without having first his, and so it would go on.
This insight into the praxeological impossibility of “universal communism,” as Rothbard referred to this proposal, brings me immediately to an alternative way of demonstrating the idea of original appropriation and private property as the only correct solution to the problem of social order.  Whether or not persons have any rights and, if so, which ones, can only be decided in the course of argumentation (propositional exchange). Justification – proof, conjecture, refutation – is argumentative justification. Anyone who denied this proposition would become involved in a performative contradiction because his denial would itself constitute an argument. Even an ethical relativist would have to accept this first proposition, which is referred to accordingly as the apriori of argumentation.
From the undeniable acceptance – the axiomatic status – of this apriori of argumentation, two equally necessary conclusions follow. First, it follows from the apriori of argumentation when there is no rational solution to the problem of conflict arising from the existence of scarcity.(...)
Furthermore, if a person were not permitted to acquire property in these goods and spaces by means of an act of original appropriation, i.e., by establishing an objective (intersubjectively ascertainable) link between himself and a particular good and/or space prior to anyone else, and if instead property in such goods or spaces were granted to late-comers, then no one would ever be permitted to begin using any good unless he had previously secured such a late-comer’s consent. Yet how can a latecomer consent to the actions of an early-comer? Moreover, every latecomer would in turn need the consent of other and later later-comers, and so on That is, neither we, our forefathers, nor our progeny would have been or would be able to survive if one followed this rule. However, in order for any person – past, present or future – to argue anything, survival must be possible; and in order to do just this property rights cannot be conceived of as being timeless and unspecific with respect to the number of persons concerned. Rather, property rights must necessarily be conceived of as originating by means of action at definite points in time and space by definite individuals. Otherwise, it would be impossible for anyone to ever say anything at a definite point in time and space and for someone else to be able to reply. Simply saying, then, that the first-user-first-owner rule of the ethics of private property can be ignored or is unjustified implies a performative contradiction, as one’s being able to say so must presuppose one’s existence as an independent decision-making unit at a given point in time and space.  (...) "
The Ethics and Economics of Private Property by Hans-Hermann Hoppe