Thursday, May 23, 2013

Hard Line Natural Rights: Alternatives To

The version of libertarianism that I refer to as the hard line natural rights position holds that individuals have an absolute right to themselves and their property, hence that any violation for any purpose is wrong. Obvious implications are that it is wrong to collect taxes for any purpose or for a starving man to steal a loaf of bread. It is a position that many libertarians not only agree with but view as defining libertarianism.

I explained my reasons for rejecting that position in Chapter 41 of The Machinery of Freedom (second edition). The Bleeding Heart Libertarians with whom I have recently been arguing reject it too. Thinking about our argument, it occurs to me that there are at least three different approaches to creating an alternative, and that part of my reason for arguing with them is that their approach strikes me as the least attractive of the three.

The first of the three approaches is to argue that the logic of libertarian rights theory leads to different conclusions than those most libertarians accept. One way of doing so is to leverage the problem of initial appropriation of unproduced resources such as land. I did not create the land my house sits on, nor did the person I bought it from or the person he bought it from, so how do I get the right to keep other people off it? It might be argued that I owe compensation to the people I am keeping off that land for violating their rights, an argument that can be used to defend  forms of taxation and/or income transfer as vindications, not  violations, of natural rights.

I have problems with all versions of that argument that I have seen, but I agree that there is a real problem. In the introduction to Machinery I argued that most income in a modern society does not come from unproduced resources, hence the solution to the problem of who is entitled to collect it does not matter very much—not a very satisfactory response, but I had no better one. Since then I have managed something a little closer to a solution, but not one I am entirely happy with. I am not convinced by the Georgists or other left-libertarians with similar approaches but I regard what they are doing as an attempt to get a modified version of libertarianism out of a solution to a real problem in the theory.

A second approach to modifying libertarian rights is the one I associate with the members of the BHL group I have been arguing with, mostly Jason and Matt. It attempts to resolve the conflict between the implications of the hard line position and their moral intuitions by importing into libertarianism ideas borrowed from modern academic philosophy. Like the first approach, the conclusion is a modified theory of rights, this time one in which the right to use force in the defense of property—this time all property, not just land—is conditional on meeting some sort of conditions of social justice.

Both approaches produce arguments that justify some amount of taxation and income transfer as compatible with rights, with the details and the justification varying within and between the approaches. The language is not identical, but if letting me use force to defend my property is unjust unless the poor are properly taken care of, then I do not have a right to both defend my property and refuse to help the poor, which makes the use of force in defense of my property a rights violation, so the essential conclusion is the same. The difference is in where they get it from.

My preference for the first approach over the second comes from my unhappiness with what I have seen of modern political philosophy, of which the work of John Rawls provides a prominent example. I have been observing it for quite a long time, having been present when the pre-publication version of one prominent variant—not by Rawls—was  being presented to an audience and had the frustrating experience of trying to persuade its author to follow his logic where it led instead of where he wanted to go. I read Rawls' A Theory of Justice early on and never was able to figure out why anyone took it seriously, beyond the fact that it provided arguments for conclusions they wanted to reach.  Reading modern philosophers I occasionally come across an interesting idea that is new to me, but not often enough to make me want to read much modern philosophy.

Which explains why when I see academic political philosophers trying to import into libertarianism ideas from modern "high" liberalism, ideas which I largely regard as pretentious fluff, my reaction is not positive. Even though they, like me, are trying to construct an alternative to hard line natural rights. For some of the reason I regard those ideas, nicely exemplified by Jason's "minimally decent lives," as fluff, see my previous post.

Which gets me to the third approach—mine. Unlike both of the others, I am not trying to produce a modified theory of rights. Like the second group, I find some conclusions of hard line natural rights strikingly inconsistent with my moral intuitions. My conclusion is that rights are not a complete account of oughts. That an act violates a right is a strong argument against doing it, but not a conclusive argument. If, to take an old example of mine, the only way of saving the human race from destruction by an approaching asteroid requires, by some bizarre set of facts, that I steal an object worth a nickle from its rightful owner, I should do it. Doing it violates his rights, which may mean that he is morally entitled to try to stop me. But a small violation of rights is more than outweighed, in my moral calculus, by an enormous benefit in consequences.

---

For a more complete account of the first approach described, see:

The Origins of Left-Libertarianism

and

Left-Libertarianism and its Critics

both edited by Peter Vallentyne and Hillel Steiner

 

32 comments:

Richard Allan said...

"Natural rights" are nonsense on stilts. The whole concept should be thrown into the garbage. To start from the position that natural rights need to be rebutted is exactly equivalent to asking someone to rebut the existence of God. It's a reversal of the burden of proof.

The correct question is "What should we do when someone is accused of doing something we dislike?" I'm a libertarian because I think the market-oriented approach to jurisprudence that allows people to choose how their disputes are resolved is best. Best, because it is most consistent with basic facts like "No-one has a divine right to rule any other" (which is indeed a fact, despite what professional muddiers of debating waters might say), and as a side note, has the most beneficial consequences.

This doesn't rely on an assumption that "people have the right to choose their own defence agency" or anything of the sort because that's the null hypothesis. Either I can choose yours and mine; or you can choose mine and yours; or we can both choose our own. The former two contradict each other so they can't both be true, but by symmetry they must both be true or both false. This doesn't constitute a proof that the third statement is correct, merely that it is the null hypothesis to be disproved.

Ross Levatter said...

David, what you describe as your way, the third way, is essentially the same as argued for recently by George Smith against Matt Z's anti-NAP view (over at libertarianism.org). The argument there essentially says (and of course, given George, with copious references to the long historical pedigree of such reasoning) that "rights" and "justice" are political concepts, while "wrong" and "ought" are larger, moral, concepts. That it is USUALLY true that what one ought to do coheres with not violating rights, but that it isn't that hard to come up with emergency situations where the moral thing is to do something unjust...something which violates rights. According to George, this is a fairly traditional position.

Power Child said...

David:

Consequentialism has always appealed more to me. However, consequentialism eventually led me away from libertarianism altogether. In the long run, it seems hard to tie consequentialism to any political philosophy, as long as the intended consequences are generally consistent. What makes it interesting, I guess, is that they aren't consistent.

martin said...

Richard Allan:

No-one has a divine right to rule any other

That's seems like fitting description of the Natural Rights approach also, so what's the big difference?

Alan McCann said...

Richard Allan: For you start from the position that "'no-one has a divine right to rule any other' is a fact" is reversing the burden of proof.

You decry this approach as a fallacy and then fall into the same trap.

Ultimately, every system of though requires some shared a priori beliefs/assumptions. Only people who have a shared set of such assumptions can really conduct logical argumentation among themselves. Otherwise, they are speaking past each other.

Hume said...

"Natural rights" simply refer to moral claims that are in some important sense 'pre-institutional', independent, not reliant on positively-recognized social or political norms. Basically, anything that one can appeal to as a standard for assessing (and criticizing) positive social norms can be called 'natural.'

Omar said...

Regarding what one might call extra-legal oughts: why do they matter? Specifically, I ought to do X, or else what? They're not optional, but then nothing changes if you don't abide by them?
Further, if our intuitions are not in line with what we might come to believe through reasoning thanks to some a priori miracle, is it not our intuitive beliefs that we should be altering? And if we were not certain that what we came to believe through philosophy was true, should we not be trying to examine foundations regardless of what our intuition says?
Also, David, how do you feel about eudaimonism à la Roderick Long? He does have some interesting points on consequentialist considerations such as the ones you've mentioned, while still defending something pretty close to the NAP, if I understand correctly.

FraserOrr said...

To me the problem is excessive bifurcation. To take the example of the starving guy stealing bread: is it wrong? Yes, it is wrong to take something someone else earned or produced, but it is not VERY wrong. it is not as wrong as, for example, murdering the baker to get his stash.

Similar to the homesteading problem. Who has the right to the original land? Nobody has the ABSOLUTE right, but the guy who develops the land and makes it productive and useful has more right to it than anyone else. Since there are obvious benefits to SOMEONE owning it, if not him, who else? For sure neither the government nor "society" has any more right to it that any other. (the Louisiana purchase being a special case.)

So the problem, to me, is the very words "right" and "wrong". Moral acceptability is a spectrum, not two bright, opposing points of light.

Anonymous said...

My take on land ownership is that it's not a question of "earning" the right to the land, in the sense implied by "mixing one's labor with the land" or the like. Locke sent us down a blind alley with that argument.

Rights in the sense libertarians mean are liberty rights, that is, rights to perform actions. But only a very limited liberty of action is possible without sustained occupancy of land. I could hunt, or forage, with no more than the right to own the animals I kill, the weapons I make, and other movables. But if I plant crops, and cannot exclude others from harvesting what I planted, my planting will go unrewarded, and I won't do it; in effect, I won't have liberty to plant. And if I improve the soil, turning forest or desert or swamp into productive farmland (the great innovation that separates Neolithic from Bronze Age farming), my payoff won't be just the next year, but years and perhaps decades later; if my tenure isn't secure I won't undertake that kind of labor, and it can't realistically be said that I have "liberty" to perform the action of farming. Property is needed to enable liberty.

Jane Jacobs wrote, in Systems of Survival, that the two basic human modes of survival are trading and taking. And it seems you have to have taking if you're going to have anything to trade. Anglo-American law long recognized this in the concept of adverse possession: if you occupy land, and hold it, and keep other people off it while you use it, you establish a right to it. The claim that someone else can have a superior right opens the door either to endless unproductive conflict, or or state seizure of land. I can't see either as a desirable approach from a libertarian point of view.

Andkon said...

One of the problems with many economists is their willing amorality that would be unacceptable in any other sphere of human interaction.

Take sex for example. Is it wrong for a man to rape a woman? What if he's really, really horny? He has no heirs! Studies indicate many women do get some physical satisfaction from even rape after all. Why not forcefully impregnate childless women so they can experience the joys of child-rearing?

Abhorrent. Yes. But why are some wary of drawing a line about what's acceptable in economics? Some actions ought to be considered non-starters in the same way that kidnapping dates is not acceptable.

Why is economics exempt from basic kindergarten ethics?

Anonymous said...

I prefer Anthony de Jasay's way of dealing with the problem.

First acquisition needs no justification, if you have a presumption for freedom (compare "guilty until proven innocent", "first come first served", "finders keepers", the institution of queueing).

First acquisition is based on an observable relationship of control/use between a human being and a bit of stuff. The question then comes for the rest of us, should we let that person stay in control of whatever they are controlling, or interfere?

With a presumption of freedom, we need justification to interfere (e.g. harm principle, negative externalities, etc.).

When we consider it our duty to refrain unless we have good reason to interfere, that's the cash-value of the person having a right to property.

It is unfortunate that Locke muddied the waters with his "proviso", because it puts the boot on the wrong foot. If there were need for a proviso, that would mean a prospective first acquirer would have to justify to us that we should let him keep control, by balancing his prospective exclusive control against the "possibility" that we might have controlled the item. Clearly this would be a process that would have no terminus (and would apply to a prospective second acquirer, and third, and so on, so the thing would never get controlled - and never have its use-value raised - compare, if we all had to justify our relative needs to get the best seat in the cinema, none of us would ever get to see the film, hence we queue).

On the other hand, if the burden of justification is on the one who would interfere with that first control (thereby denying exclusivity), then he has to have a concrete reason why he is justified (e.g. my use of the item is objectively, provably harmful, etc., and should therefore not be allowed to be exclusive).

IOW, everyone's been looking down the wrong end of the telescope when it comes to the question of where justification is necessary.

RJM said...

What about that:

A peaceful approach to human interaction results in certain principles, for example property.

Sometimes peaceful interaction does not result in property. I've heard of the example of native americans who rather shared their land than owned it. The reason was, they were nomads and rather ignorant to the fact that other people might use the land they used before.
Another example is the surgeon who cuts me open when I am not even able to utter my consent. He clearly violates most basic ownership rights.

So what is peaceful interaction than? Well in 99% of all cases we can describe it as respecting each others (property) rights.
For the other 1% of human interaction there might not be any general definition of what "peaceful interaction" implies.

So when David steals to save the world, he made any absolutist argument absurd. In my everyday life this example is absurd and the property principles are quite important. Again when I argue for a even more peaceful future, e.g. one without state.

Anonymous said...

In answer to whswhs, the right to tenure in improvements does not imply the right to absolute ownership of the land, a point made by Henry George. If I plant grain on a piece of land, I should have the right to harvest the grain, or else I am unlikely to plant in the first place. But do I also acquire permanent ownership of the land? Can I therefore announce that anyone who wants to build a skyscraper on the plot of land must pay me? I believe not.

Rebecca Friedman said...

Andkon,

I don't know what branch of logic you're using for those arguments, but it's not economics.

Economics has something called revealed preference, which means that we can tell what a person wants from what they do. If the lady in question is refusing sex, that indicates that the cost to her is higher than the benefit - therefore, raping her is wrong; -the fact that she refuses alone is sufficient to indicate that all the potential benefits you list are less than the cost-.*

And yes, you can say that argument is cold; rape should be wrong on its own merits. But note that I've just derived the exact same conclusion you did... and I also, in doing so, derived a reason to disprove the counter-arguments you designed. A reason rather more intellectually satisfying than "because it's wrong." You can't really have an argument with someone who disagrees with you using "because it's wrong" - with arguments derived from economics, you can.

In other words, economics is "exempt from basic kindergarten ethics" because, given a desired end-point (for example, to take the one you are using, maximizing utility) it is a -way of deriving- ethics. Kindergarten ethics - for which I read some variation of "you don't do [X] because it's wrong" - is, inherently, intellectually unsatisfying. It is also useless for persuading people who disagree. ("OK, it's wrong, but what if not doing it results in A, B and C which are worse?") If you want to be able to answer those questions, you need more complex arguments. Economics gives us one logical framework for making those arguments.

And yes, again, considering the benefits of actions we consider horrifying as genuine benefits may be disturbing. But if you want a real answer, you need to do it. If you don't - if you take a pure rights position - you end up with it being wrong to steal a nickle to save the world.

*At least, the benefit to her. If you allow transfers, then if the combined benefit of the sex is greater than the combined cost, the individual who is getting the greater benefit should be able to compensate the other individual sufficiently to get willing consent. If he (presumably) can't do so, then we can logically conclude the combined benefit (ie, benefit to both individuals) is less than the combined cost, so the sex should not take place.

Yes, this means economics + utilitarianism does not prohibit prostitution. (Unless you can make a strong argument based on externalities).

Andkon said...

Rebecca, you're missing the crucial distinction: you're not thinking of the preference of the rapist.

When you argue that taxing Y is inefficient, you're allowing for the aggressors' (the actual takers and recipients of the taxes) preferences to have weight. And it's quite hard to make an argument against something like Social Security then: the people receiving it now are getting three times out what they put in. How is that inefficient for them? What possible argument could work on them?

"...you end up with it being wrong to steal a nickle to save the world."

In what realistic situation do you get huge payoffs for small costs... with the condition that you cannot resort to initiating force? No one has a nickel to spare willingly to save the world?

Friedman does this "perfect is the enemy of good" straw man in Chapter 41 when he equates a single molecule of C02 as a property rights violation under first principles. Is there any insurance company that would draw the line at something so ridiculous?

The irony is that the NAP solves about 99% of property rights problems concisely without needing a lengthy consequentialist analysis for every possible action.

Rebecca Friedman said...

Andkon,

"And it's quite hard to make an argument against something like Social Security then: the people receiving it now are getting three times out what they put in. How is that inefficient for them? What possible argument could work on them?"

... Um, I already referenced revealed preference. If everyone contributing to social security chooses to do so voluntarily, and the only costs are being paid by people who choose to pay them, it's fine. That isn't the case, and hence it's not known to be efficient (and can be presumed inefficient, since coercion is necessary). What am I not conveying here? The benefit to the people getting the payoff matters, obviously. But if it matters enough, they will be able to compensate those paying the costs to agree to it. If they can't, then it clearly doesn't matter enough. What is the problem with this?

"In what realistic situation do you get huge payoffs for small costs... with the condition that you cannot resort to initiating force?"

Who said you couldn't? In the example I was referencing, theft is arguably initiating force. The question is whether it is always wrong to initiate force, or whether there are circumstances when not doing so is worse. As for large payoffs/small costs... one of the other posters had the very good example of shoving someone out of the way of danger. Shoving someone is usually not appropriate - however, if there's a car coming...

"Is there any insurance company that would draw the line at something so ridiculous?"

I don't see how this is relevant. Why does the insurance company matter? US Law, as it exists, refuses to draw the line at quite a number of things I think are extremely ridiculous. Why should I take an insurance company's judgment as any more valid?

(The next paragraph is an attempt to answer my best guess at what you meant by that, which is "no reasonable person would consider applying the principles at such absurd extremes." If that guess is wrong, please feel free to skip it.)

If principles, taken to their logical conclusions, end in absurdity, I don't feel that "Well, that's absurd, the problem is that you extrapolated it past the point anyone reasonable would do so" is a good response. "Why did that happen, and does that absurdity tell us about any problems with less-extreme applications of the principles" is a better one. If principles are meant to apply in all cases, they need to apply in all cases. If they aren't universal, don't call them so - and if that's the case, I don't see how you can reasonably object to someone else trying to figure out an alternative that -is-. If you're relying on common sense to explain bits of your philosophical system, you've already abandoned the attempt to make a coherent system - which seems to me an attempt worth making.

"The irony is that the NAP solves about 99% of property rights problems concisely without needing a lengthy consequentialist analysis for every possible action."

But does it tell you why?

Anonymous said...

ndrosen: Planting grain and harvesting it a year later is only the starting point, as I thought my comment made clear. The very first grain was planted in the highly fertile soil of river valleys. But later farmers developed techniques for manufacturing fertile soil able to support a crop of grain, or multiple crops, from the slash-and-burn cultivation of some tropical societies (but also, I believe, early Finland!), which produce a field fertile for five or ten years, to the land clearing techniques of medieval and later agrarian societies, where cleared land remained valuable for generations, given ongoing care (fertilization, irrigation, and plowing, for example). People undertook the effort of clearing land and making it fertile because they expected to retain the use of it; if you cut tenure off, you have decreased the incentive to create land, and indeed the freedom to create land.

Now, if land loses its fertility, it will stop being cultivated, since farmers want to eat and will go elsewhere to seek good land. And in that case the land can sensibly be said to have reverted to "public domain" or become unowned. But that isn't all that common. More often, the land remains in cultivation, while population increases, and eventually demand for nonfarming uses becomes high enough for the farmer to be offered a price they can't refuse. There is no obvious point in this process at which the land has ceased to be used, or at which the land can be taken for a different use without denying the farmer's freedom to cultivate.

Did the land's value increase through the farmer's unaided efforts, or through the growth of society around the farmer? Obviously the latter. But so what? My labor as a copy editor is worth vastly more in our current society than it could possibly have been in ancient Rome, or a tribal village in the Neolithic; and that value comes from the market that surrounds me. But that doesn't strike me as entitling other people to take control of my labor away from me by making me a slave.

Will McLean said...

"The irony is that the NAP solves about 99% of property rights problems concisely without needing a lengthy consequentialist analysis for every possible action."

"You can't take my property" is concise. Defining what property you justly hold, and what rights that holding entails, is not. The idea that a private owner can somehow acquire *absolute* control of unproduced property is particularly problematic for everyone but hard line libertarians.

Andkon said...

Rebecca,

I read your response and replied but I got tangled up... it's perhaps easier to go back and focus on this:

"If the lady in question is refusing sex, that indicates that the cost to her is higher than the benefit - therefore, raping her is wrong;-the fact that she refuses alone is sufficient to indicate that all the potential benefits you list are less than the cost-.*"

But isn't that just the moral argument? Compare:

"If the woman in question is refusing [SS TAX]>, that indicates that the cost to her is higher than the benefit - therefore, [TAXING] her is wrong; the fact that she refuses alone is sufficient to indicate that all the potential benefits you list are less than the cost-"

I don't see what difference we have then. Aren't you assuming that violating the individual's person or property is a non-starter?

Will McLean said...

If the individual owner of property can require payment for its use, why can't the owners of the commons insit on payment for its use?

Andkon said...

It depends on what specifically you mean by the commons. Any examples?

David Friedman said...

Will:

I'm not sure that "owners of the commons" makes sense, since the fact that something is a commons means nobody owns it and anybody can use it. It would make sense, if 100 people have common access to some piece of property, for 99 of them to agree to some payment in exchange for giving up their right to use it and making it the exclusive property of the 100th.

But that doesn't work short of unanimity, because if 90 people make the agreement, there are still 9 left with the right to use the property that the 100th wants treated as his private property.

Which gets to part of my problem with the Georgist argument. Not only do I not own the unproduced property, we don't own it either, since we didn't produce it.

Will McLean said...

"I'm not sure that "owners of the commons" makes sense, since the fact that something is a commons means nobody owns it and anybody can use it."

That seems like a poor description of of the English commons in its most literal form. Use of the commons was limited to a finite group: the tenants of a particular manor, who had rights to use the commons for specified purposes. The lord of the manor owned the rents, which presumably reflected the benefit to the tenants of their customary use of common land.

martin said...

Will,

The idea that a private owner can somehow acquire *absolute* control of unproduced property is particularly problematic for everyone but hard line libertarians.

On the contrary, "hard line" libertarians require at least some work for land to initially become someones property, while many (not all) non-liberarians have no such requirement, as long as the ownership is backed by the state.

Furthermore, many people have no problems at all with "public ownership" claims that go way beyond any private ownership claim any "hard line" libertarian would support. Or do you think the US government 'mixed it's labor' with all of the US territory?

martin said...

Will,

Defining what property you justly hold, and what rights that holding entails, is not.

Well, it's a theoretical problem, sure. But in practice it's not so difficult to stay of of other people's lawns, is it?

Unknown said...

In the vast majority of cases that I have encountered the collision between property rights and moral intuition comes from extreme non-linearities of individual preferences near zero. A starving person is willing to pay an enormous price for immediate access to nutrients and there might not be enough time for competitive bidding.

The standard libertarian argument is that allowing the exploitation of this and similar non-linearities provides a strong incentive for actually helping those who starve. But that is not the whole story; it also provide a strong incentive to make and keep people on the edge of starvation and hamper their access to the open market. Moreover, it also provides resources (the differences between the price offered by the starving person and the price on the open market) for creating barriers to access to the open market for those who are near starvation.

While I do not for a moment think that government-mandated minimum wage or anti-usury laws and somesuch are the right solution, I do ackowledge that there is a problem here that needs to be solved. I think that the solution is either some consistent application of the Common Law standard of consideration for contracts to become binding or to consider those near starvation (or any similar life-threatening condition) to be of limited contractworthyness. Thus, Esau could successfully reclaim his birthright from Jacob.

Will McLean said...

Martin:

Most people don't base their beliefs about land tenure on just so stories about labor mixing. Land claims, both public and private, based on pre-1948 national annexations are accepted as less unjust than any effort to reverse them.

My right to eject trespassers on my property is based on common law and statute, not hard line libertarian theory, which saves me from having a long argument with a squatter about his natural right to perform slash-and-burn agriculture on the unimproved portion of my property.

martin said...

Will,

Thank you for proving my point.

Anonymous said...

Looking at the comments above, again, I'd recommend people look at Anthony de Jasay's treatment of the matter, it's much clearer than any other IMHO.

We really must get clear where the burden of justification lies.

People don't need to justify whatever it is they want to do. What could possibly place the burden of justification there? And how could it possibly be discharged?

What requires justification is any break in the above presumption of freedom.

If somebody is provably doing harm in some way, that's a good justification to intefere with their freedom. Otherwise, leave them alone.

That's where the exclusivity of the system of several property system comes from - from there being no good reason to intefere with anyone's control or use of whatever they're controlling or using, until and unless they do harm.

Libertarians have to stop giving up the fight before it's even started by allowing that one must have a reason to leave people be.

No, you need a reason to interfere, that's the only place where reason and justification come in. Absent that, interference is simply aggression.

This also handily deals with "claiming the Moon" examples. What objective, observable process of use or control are we being asked to let be, when someone claims exclusive use of the Moon?

If there's no "there" there, no objective, observable process of control or use, then there's nothing to let be, and no claim of exclusivity (which amounts to the request that we let be).

David Friedman said...

"Libertarians have to stop giving up the fight before it's even started by allowing that one must have a reason to leave people be."

The counter argument is that when you eject someone from "your" property you are not leaving him be,hence you need a reason.

martin said...

David:

The counter argument is that when you eject someone from "your" property you are not leaving him be,hence you need a reason.

He's interfering with your use of the property, you're interfering with his interfering. Either interfering is OK, in which case interfering with interfering is also OK, or it is not. If interfering is not OK, countering it should be allowed or else it's a kind of toothless prohibition. People who think that interfering is *ALWAYS* prohibited (even if only to counter interference) would object against your interfering, but would not be able to do much about it because their interfering with your interfering would of course also be prohibited.

Anonymous said...

"The counter argument is that when you eject someone from "your" property you are not leaving him be, hence you need a reason."

No, the ejectee first needed a good reason to be interfering with your ongoing use or control of whatever you are using/controlling (which is what the social rule of calling it your "property" and leaving you in control of it is based on, or should be based on, rather). If they don't have a good reason, they are the first to break the rule of letting each other be (they are "initiating aggression", although that's a potentially misleading way of putting it). They "started it".

It's a kind of principle of "inertia of freedom" - it's the one who would propose knocking you out of your orbit who needs to justify themselves (erm, perhaps I shouldn't be using a physics analogy in front of a physics prof, but what the hey :) ). They might indeed be justified - freedom cannot be an absolute - but they'd need a good reason.

What the ejector does need a good reason for is the proportionality of their response, but they do not need to justify responding at all, because they are indeed responding to something, something which occurred prior to their response.

The ejector needs a good reason for the proportionality of their response because there's a kind of intuitive mandala of sanctity of control - obviously one's control of one's own body is at the centre of the mandala, the first thing that one finds in a state of nature to control, the first thing one ought to be left in control/use of; as you get further and further away from that "inalienable" (for now, but cf. Vernor Vinge :) ) right at the centre, everyone intuitively understands that there's a weaker and weaker case of some kind.

But this radiating weakness doesn't pertain to the use/control in and of itself (and to the right to some response), it pertains to a kind of allowable proportionality of response to its breach. Everyone intuitively understands that offences against the body justify a strong response; offences against property normally so-called also justify a response, but killing someone for simply trespassing would be considered by most sane people disproportionate (depending on the circumstances, obviously if it's dark at night, a rough neighbourhood, you saw a glint of metal, etc., etc.). Also, even though the ejectee is in the wrong, there's a certain sanctity of their body that has to be respected, which still has some weight, to be weighed against their offence - again, proportionality has to be justified, although response as such doesn't have to be (it being a right).

On the other hand, "squatters' rights" are a good old part of law - everyone intuitively understands that a piece of property that's been left untouched, and without owner's response for 10 years or more is on the absolute outside fringe of the mandala. To say that the owner still has a relationship of control or use with the property that has to be let be, gets really tenuous to maintain - it approaches the "claiming the Moon" example.

Right cannot be based on possibility of use, maybe use, wanting to use, could have used, etc., etc., because such arguments could have no objective test, and therefore no end, and therefore no justice could be based on them. Right has to be based on observable relations of use/control between a person and a thing - that's what can be broken, interfered with, aggressed against, etc. Just like a beaver building a dam, human use and control of things is an objective, observable thing that occurs in a state of nature, and that's what the social rule has to be based upon - otherwise, as I said, there's no "there" there, nothing that can be allowed (by the rest of us) to be exclusive or not, nothing to let be; therefore, no question of right (because no concomitant obligation on the rest of us).