We live in a world where we must employ scarce resources in order to survive and thrive. No two objects can occupy the same space at the same time or be used for mutually exclusive purposes at the same time. This implies that space and our bodies are scarce resources. No two of us can stand in the same place at the same time, use the same tools or work area for mutually exclusive purposes, use the same land to live on or harvest resources from at the same time, or consume the same rivalrous good. Whenever two or more people try to do any of these things, conflict arises. Conflict can lead to violence, injury, death, and all kinds of misery. Given that things like peace and harmony are to be preferred over things like conflict and violence, the facts mentioned above should inform us as to the proper purpose of law. I'll state the proper purpose of law as that of minimizing conflict. Law can serve as a standard by which to adjudicate disputes, and as a guide by which conflict can be avoided. Using law for that purpose, and that purpose only, would seem to maximize peace and harmony. Using law for any purpose which is incompatible with that purpose may, and in many cases tends to, create conflict rather than preventing or mitigating it. A working definition of ownership is; the exclusive right to control a given object or scarce resource. At the point of application, law is always used to adjudicate disputes between parties. The First User Principle is embraced by all libertarians, assumed by all emergent legal systems including but not limited to common law systems, and simultaneously assumed and rejected by top-down positivist systems. Libertarians embrace the First User Principle for many reasons. We see it as the most likely way to achieve just outcomes from litigation, but also as the most reliable standard by which to achieve and retain consistent, predictable law. The way the First User Principle is most commonly arrived at is by asking, with respect to a given dispute over some scarce resource; who has the better claim to it? In a dispute over a person's body, some principles that we all assume and agree on become easy to see. If Bill wants to assert control over Ted's body, we have a dispute over ownership(i.e. who has the exclusive right to control) of Ted's body. Most of us assume that should be Ted; but why do we assume that? More to the point; are there any universalizable principles that we can derive by answering the question of why we assume it? It is certainly true that Ted is in possession of his body at the time of the dispute, but trying to draw a principle from that fact alone would lead us inexorably to a standard by which might makes right, since we can each rightfully own anything we can be found to possess at a given time regardless of how we came to possess it, in which case we wouldn't need law or reason for anything. We can, however, universalize principles from the facts that Ted had control over his body before Bill did and that it was necessary for Bill to initiate force against Ted to bring about the conflict in the first place. Say we settle this dispute and, in so doing, establish a legal principle that whoever comes to control a thing first becomes its owner. Later, Bill tills a field and plants some corn. When the corn begins to ripen, Ted comes along and harvests half of it. Now we have another conflict and another dispute, Bill v. Ted. If we apply the exact same line of reasoning we did to Ted v. Bill, we will come to the the same opinion we came to in Ted v. Bill, that Bill, in this case, is the lawful owner of the corn in Ted's possession because Bill has the better claim because Bill had it first because assuming that the current possessor is the owner would defeat the purpose of law. There are other questions we could ask when deciding Bill v. Ted. For example; what would Bill do with the corn if he were the owner? What would Ted do with it? Let's say Ted has a family of four and Bill has a family of three. Imagine we conclude that, since Ted has a bigger family to feed, he should be the owner of the corn and, in so deciding, establish the legal principle that whoever can provide the greatest utility for the greatest number of people with a thing becomes its owner. By this principle, Ted has no need to work. Since his family is larger than Bill's, all he needs to do is take everything Bill produces. Since Ted is incentivized by this principle to take from Bill, the principle will create conflict rather than preventing it. Bill would quickly lose all incentive to work. Everyone is incentivized to grow their families as quickly as possible and take from others rather than working to produce anything. It defeats the purpose of law. In fact, it makes a mockery of everything we're trying to do when we establish law. We could go through other hypothetical scenarios but, if we do so for the purpose of establishing universalizable principles by which conflicts can be peacefully resolved and by which conflict, according to those principles, will be minimized, we will always return to the First User Principle. The question of ownership cannot be avoided by any legal system. Saying that everyone owns everything is the same as saying nothing about it and provides no standard by which conflicts can be resolved or prevented. Any standard other than the First User Principle tends to create, rather than prevent, conflict. As libertarians know, libertarian legal theory can't be covered in a single thread, let alone a single post, so I'll stop here for this one. _____________ Key Points: The proper purpose of law is to minimize conflict. Using law for anything incompatible with its proper purpose will reduce peace and harmony and create conflict and injustice. At the point of application, law is always used to adjudicate disputes between parties. Any standard other than the First User Principle tends to incentivize, rather than prevent, conflict. ________ Objections of Central Planners Something often overlooked is the reason we need law in the first place. That reason is precisely to prevent or mitigate the conflicts that we know will arise with all of us vying for the same scarce resources. Existing for such a reason, it only ever sees application when there is a dispute. This is why, even in the legislation-based system we have now where planners have taken control, every case consists of disputing parties, a complaining party, or "plaintiff", moving(taking action) against an accused party, or "defendant". The role for equity to play must be with respect to those disputes. That's why I stated the purpose of law the way I have. That is where disagreement will really lie, and what planners cannot afford to come to terms with. They would have to posit some other purpose of law. But what could that be, other than that law is a tool by which planners can impose their own vision for society as a unit, as a ruler over subjects or a master over pets, on everyone else?