Non-libertarians often find libertarianism baffling. Notice the fundamentally puzzled tone of so many critiques of libertarianism – like, for example, this one by Don Herzog (I choose it more or less at random):
There’s something endearingly toughminded, if that’s not an oxymoron, about libertarianism. At the same time, for the same reason, there’s something unbelievably monotonous about it. Whatever the issue, libertarians can be relied on to complain that people’s rights, especially their property rights, are being violated. Violations of rights, apparently, are everywhere: in laws prohibiting the sale and possession of crack, in zoning regulations, in antitrust statutes, in any and all sorts of economic redistribution, even in the public ownership of roads and taxation itself. 
The unspoken subtext is: why on earth would anyone believe this? To the nonlibertarian, libertarianism seems simply weird in its insistence that people have, on the one hand, no welfare rights at all – and on the other hand, property rights so robust that nearly every law on the books stands in violation of them. Libertarianism, in its apparent stark and fanatical focus on negative rights above all else, irresistibly reminds non-libertarians of the contending schools of Presocratic philosophy, intemperately insisting that everything was water, or fire, or motion, or rest. Libertarian policy prescriptions can easily seem to express a kind of fundamentalist mind-set comparable in strangeness and extremism (though of course not in content) to that of the Taliban.
This appearance, I shall argue, is illusory. Regardless of whether libertarians are right or wrong, their viewpoint, I contend, derives not from an alien set of values, but rather from a quite ordinary set of values coupled with a recognition of the logical implications of those values. In Section One I shall explain why libertarians favour negative rights over positive ones; in Section Two I shall turn to the application of this position to property rights.
I. One Right to Rule Them All
Libertarians believe  that there is, fundamentally, only one right: the right not to be aggressed against. All further rights are simply applications of, rather than supplements to, this basic right. Hence the vast panoply of other rights – positive rights, welfare rights – recognized by existing political regimes is dismissed as illegitimate.
This view seems mysterious to non-libertarians. More specifically, the libertarian position strikes many critics as puzzlingly one-sided. Freedom from aggression is a good thing, certainly; but so are freedom from hunger, freedom from disease, and freedom from poverty. Why not recognize rights in all these cases? What sort of lopsided view would one have to have of human life, in order to think that aggression is, but hunger, disease, and poverty are not, serious enough evils to take into account in devising a system of rights?
In what follows I offer an explanation of the libertarian position. Although I myself accept that position, I shall not be arguing for its truth; but I do hope to show that the position is not especially puzzling or mysterious, and that it does not depend on an implausible assessment (or indeed any assessment) of the relative badness of aggression compared to other evils.
The libertarian position comprises two distinct claims: first, we have a right not to be aggressed against (call this the Positive Thesis); second, we have no other rights (call this the Negative Thesis). While neither of these theses is uncontroversial, the Negative Thesis is likely to meet with far more dissent than the Positive Thesis. But for the libertarian, any such differential response must express a confusion, because the Positive Thesis turns out to entail the Negative Thesis (at least with the help of some truistic auxiliary premises).
For libertarians, the concept of rights belongs in the first instance to the realm of interpersonal ethics, and applies to the political realm only secondarily. That is because, for libertarians – as for the liberal tradition generally – rights are not the product of a political regime, but are prior to such regimes and constitute a constraint on them. Hence rights cannot without circularity be defined in terms of the purposes of a political regime. If political regimes are constrained by certain pre-existing rights, and indeed have as one of their purposes the protection of these rights, then it must be possible to describe what these rights require without presupposing the existence of a political regime. A crucial feature of libertarian political theorizing is the insistence that not just the precise nature, but the very existence, of political authority requires justification and cannot simply be assumed. If we start from the basic natural rights that human beings would have in any social context, including a state of nature, then the specification of a particular political regime cannot subtract from that array of rights; but then it cannot add to it either, for, as we shall see, the addition of one right always involves the subtraction of another.
How, then, are rights to be defined, if all reference to political institutions is to be omitted? To have a right is to have a moral claim against another person or persons; but not every such moral claim is a right. My having a right to be treated in a certain manner involves, at least, other people having an obligation so to treat me; but it must involve more than this, for not every such obligation has a right as its correlate. I have an obligation to be polite to my associates and grateful to my benefactors, but they have no right (except metaphorically) to my politeness or my gratitude.
It might be suggested that the correlate of a right is not just any obligation, but a legal obligation. Certainly this answer is on the right track, and is in line with the term’s historical associations, but as it stands it is inadequate. For, once again, we cannot without circularity define rights in terms of legal concepts and institutions if we wish to use rights as an independent standard for and constraint on legal institutions. But the reference to legal obligations does point to a crucial fact: the obligations that are correlated with rights differ from other obligations in being legitimately enforceable. If you wish to get me to honour a moral claim against me, you are free to lecture me, cajole me, or pay me, but only if the moral claim is a right may you use force as a means of securing my compliance. Hence X’s having a right against Y comprises both an obligation component and a permissibility component: the obligation on Y’s part to treat X in a certain manner, and the permissibility, on the part of X or of someone acting on X’s behalf, of forcibly compelling Y to treat X in that manner. (Note that the permissibility of enforcing a right does not entail the permissibility of exercising that right. I have the right to publish and distribute Nazi propaganda; it would not be permissible for me to exercise that right, but it would nevertheless be permissible for me, or my agent, to fend off by force anyone who proposed to suppress that right.)
But if rights are defined in terms of force, then there are conceptual constraints on what we can say about the relation between rights and aggression. For aggression and force are conceptually linked; aggression is initiatory force – or conversely, force is that mode of conduct which, if initiated unilaterally, counts as aggression. (To be sure, the precise contours of these two concepts stand in need of specification; but the vagueness of one is the vagueness of the other. Any doubts as to whether a particular course of action counts as force will be mirrored by doubts as to whether the initiation of that sort of conduct counts as aggression.) 
Now libertarians, as we have seen, accept the Positive Thesis that we have a right not to be aggressed against. Some libertarians accept this thesis on primarily deontological grounds, pointing, e.g., to the Kantian injunction not to treat persons as mere means to the ends of others, or the Lockean principle that we are not “made for one another’s uses.” Other libertarians accept the thesis on primarily consequentialist grounds, pointing to the beneficial results of voluntary relationships and the harmful results of coercive ones. 
But whatever the grounds, even those who reject the Positive Thesis will agree that it is attractive and that there is nothing mysterious about embracing it; it is the Negative Thesis that seems so outrageous. But what the libertarian is claiming is that the possibility of accepting the Positive Thesis while rejecting the Negative Thesis is precluded by the logical structure of the concepts involved. If people have a right not to be aggressed against, then people have a right not to be subjected to any initiatory use of force.
Consider the implications. What would have to be true if there were, in addition, some right other than the right not to be aggressed against? This would have to be a right to be treated in manner X, where failing to act in manner X does not constitute aggression, or initiatory force. (For if failing to act in manner X did constitute initiatory force, then the right to be treated in manner X would be a mere application of, rather than a supplement to, the right not to be aggressed against.) But if failing to act in manner X does not involve initiatory force, then either it involves non-initiatory force, or it does not involve force at all.
Suppose that failing to act in manner X does not involve force at all; in that case, compelling someone to act in manner X would constitute initiatory force, i.e., aggression, since it would be a use of force in response to something other than force. Once we grant the Positive Thesis and recognize a right not to be aggressed against, there can then be no right whose enforcement would involve compelling conduct whose non-performance would not involve the use of force.
Suppose instead that failing to act in manner X does involve force, but not initiatory force. Then what sort of force is it? It must presumably be a forcible restraint of another’s aggression; for otherwise it would be initiatory. But the forcible restraint of another’s aggression is permissible; for once we have granted the existence of a right not to be aggressed against, then we have granted the permissibility of forcibly restraining others’ aggression – since, as we’ve seen, the right not to be aggressed against comprises both the obligation not to aggress and the permissibility of using force to secure such non-aggression. Since forcible restraint of others’ aggression is permissible, there cannot be a right to forbid such forcible restraint.
If an activity involves no use of force, then there can be no right to suppress it by force, since such a use of force would be aggression, and so would violate the obligation component of the right not to be aggressed against. And if an activity involves a non-initiatory use of force, then once again there can be no right to suppress it by force, since such a use of force would violate the permissibility component of the right not to be aggressed against. Hence the only activity whose forcible suppression is consistent with the right not to be aggressed against, is aggression itself. But there can be a right to be treated in manner X, only if forcibly compelling people to act in manner X is permissible, which in turn is possible only if failing to act in manner X is an activity whose forcible suppression is permissible. Thus if aggression is the only activity whose forcible suppression is permissible, then refraining from aggression is the only activity whose performance may legitimately be compelled. It follows that by recognizing a right not to be aggressed against, we have thereby ipso facto ruled out the existence of any other right.
Let me state this argument somewhat more formally:
- Every person has the right not to be aggressed against by any other person. [The Positive Thesis.] (Premise.)
- Aggression = initiatory force. (Premise.)
- X has a right against Y to be treated in manner Z just in case a) Y is obligated to treat X in manner Z, and b) it is permissible for X, or X’s agent, to use force to compel Y to treat X in manner Z. (Premise.)
- Every activity constitutes either initiatory force, non-initiatory force, or non-force. (Premise.)
- An activity constitutes non-initiatory force just in case it is a use of force to restrain others from initiating force against one. (Premise.)
- Whatever it is permissible to do, it is impermissible to suppress by force. (Premise.)
- Doing something is obligatory just in case not doing it is not permissible. (Premise.)
- If an activity constitutes non-force, then forcibly suppressing it constitutes initiatory force. (Premise.)
- If X has a right against Y to be treated in manner Z, then it is permissible for X, or X’s agent, to use force to compel Y to treat X in manner Z. (3)
- Every person has the right not to have force initiated against her by any other person. (1, 2)
- Every person is obligated not to initiate force against any other person, and it is permissible for any person, or the agent of any person, to use force to restrain others from initiating force against that person. (3, 10)
- Every person is obligated not to initiate force against any other person. (11)
- It is permissible for any person, or the agent of any person, to use force to restrain others from initiating force against that person. (11)
- If X has any right against Y other than the right not to be aggressed against by Y, then there is a way of acting, Z, such that Z does not constitute aggression, and yet it is permissible for X, or X’s agent, to use force to compel Y to treat X in manner Z. (9)
- If X has any right against Y other than the right not to be aggressed against by Y, then there is a way of acting, Z, such that failing to act in manner Z does not constitute initiatory force, and yet it is permissible for X, or X’s agent, to use force to compel Y to treat X in manner Z. (2, 14)
- If X has any right against Y other than the right not to be aggressed against by Y, then there is a way of acting, Z, such that failing to act in manner Z constitutes either non-initiatory force or non-force, and yet it is permissible for X, or X’s agent, to use force to compel Y to treat X in manner Z. (4, 15)
- It is permissible for any person to engage in non-initiatory force. (5, 13)
- It is impermissible for any person forcibly to prevent any other person from engaging in non-initiatory force. (6, 17)
- It is impermissible for any person to initiate force against any other person. (7, 12)
- It is impermissible for any person forcibly to prevent any other person from engaging in an activity that constitutes non-force. (8, 19)
- It is impermissible for any person forcibly to prevent any other person from engaging either in non-initiatory force or in non-force. (18, 20)
- There is no way of acting, Z, such that failing to act in manner Z constitutes either non-initiatory force or non-force, and yet it is permissible for X, or X’s agent, to use force to compel Y to treat X in manner Z. (21)
- There are no rights other than the right not to be aggressed against. [The Negative Thesis.] (16, 22)
The frequent charge that libertarians recognize too few rights – that they should recognize positive rights in addition to negative ones – is thus an empty one. Since every right carries with it a permissibility of enforcement, to introduce a new right is always to introduce a new permissible use of force to restrict people’s activities, and thus to close off forcibly certain choices that were previously open to them. If I gain a right to be treated in manner M, you must correspondingly lose the right not to treat me in manner M. Hence every time we add a right here, we ipso facto subtract a right there; the total quantity of rights can thus be rearranged, but not increased. Perhaps libertarians recognize the wrong rights; but it makes no sense to complain that they recognize too few.
Because libertarians acknowledge only negative and not positive rights, critics often assume that libertarians must also, bizarrely, acknowledge only negative and not positive obligations. But of course libertarians acknowledge both kinds of obligations.  It’s just that libertarians understand negative obligations to rule out the enforceability of positive obligations; the ban on positive rights derives from conceptual constraints inherent in our negative obligations, not from any privileging of negative obligations over positive ones. (The libertarian is not, for example, committed to regarding freedom from aggression as more important than any other value.)
The Positive Thesis initially seemed more plausible than the Negative Thesis; but once we grant premises 2 through 8, then we can see that the Positive and Negative Theses stand or fall together. Of course premises 2 through 8 are not immune from challenge; but they do have, I submit, a certain luminous obviousness about them. The most likely target for the non-libertarian, then, is premise 1, the Positive Thesis, which for many will lose much of its initial plausibility once it is seen to commit us to the Negative Thesis. But the non-libertarian will then need to face and overcome the deontological and consequentialist arguments for the Positive Thesis. I think those arguments are weighty ones, but defending them is not my present concern; I am simply attempting to delineate the logical structure of libertarianism, to show how its claims hang together.
II. The Logic of Property
A fuller understanding of the libertarian conception of non-aggression requires some attention to the issue of property rights. Libertarians, notoriously, condemn as unrightful any interference with private property. But how is this connected with the libertarian position on aggression? After all, someone could acknowledge a right to be free from initiatory force, but deny that seizing someone’s external possessions counts as initiatory force, or indeed as force at all.
Let us first observe that insofar as a property right is the right to exercise control over some external  resource, the defender of welfare programs, economic regulation, and redistributive taxation is as much a proponent of property rights as the libertarian. Someone who claims that the less affluent have a right to the excess wealth of the more affluent (or, for that matter, vice versa)  is asserting a right, on the part of one group, to exercise control over certain resources that have heretofore been under the control of another group. Hence the libertarian and the welfare-statist disagree, not about the existence of property rights, but about the transfer conditions of those rights.  For the libertarian, a property right can pass from X to Y only if both parties consent to the transfer;  for the welfare-statist, such a transfer of property rights can be triggered not only by mutual consent, but also by, e.g., Y’s need, regardless of X’s consent. Hence the libertarian rejection of positive rights does not ipso facto rule out the existence of welfare rights or a welfare state, at least not without further argument; for the welfare state could be seen as securing the negative right of the needy not to be prevented from helping themselves to resources to which they are entitled. 
What, then, explains the libertarian’s dissent from the welfare-statist position?
Since libertarians accept the Positive Thesis, they can acknowledge a right to control external resources only insofar as interference with such control would constitute initiatory force. This brings us back to the question of specifying what counts as force. Imagine a world in which people freely expropriate other people’s possessions; nobody initiates force directly against another person’s body, but subject to that constraint, people regularly grab any external resource they can get their hands on, regardless of who has made or been using the resource. Any conception of aggression according to which the world so described is free of aggression is not a plausible one. 
Hence it follows that we are committed to recognizing, as instances of initiatory force, some forms of interference with one’s control over external resources, even if no bodily assault on one’s person is involved. But if such forms of interference constitute initiatory force, then it must be permissible to interfere with them; hence it follows that we must also recognize some forms of interference that do not constitute initiatory force. In short, we are committed to a system of property rights – that is, a set of principles determining when one may, and when one may not, interfere with a person’s control over some external resource.
The question, then, is: what system of property rights has the best claim to be an instantiation of the right not to be aggressed against? I shall not argue that the libertarian system is decisively superior to the welfare-statist system on this count; I shall merely attempt to show that there are certain difficulties in regarding the welfare-statist system as an instantiation of the right of non-aggression, and that the libertarian system is not subject to these particular difficulties.
Libertarian property rights are, famously, governed by principles of justice in initial appropriation (mixing one’s labour with previously unowned resources), justice in transfer (mutual consent), and justice in rectification (say, restitution plus damages). 
It is easy to see how the right not to be aggressed against will be interpreted here: I count as initiating force against a person if I seize an external resource that she is entitled to by the application of those three principles. If she is not entitled to the resource under these principles, but is in possession of the resource anyway, then my seizing the resource counts as force, but not as initiatory force, so long as I am acting on behalf of whichever person is entitled to the resource; otherwise I am initiating force against that person. 
Whether or not this is the most defensible instantiation of the right not to be aggressed against, it is at least a possible and coherently intelligible way of instantiating that right. 
It is not clear that the same can be said for the welfare-statist alternative. The welfare-statist may of course claim that it is aggression to cling to one’s resources when there are others who need them more; but what could this mean in practice? Suppose that the disparity of wealth between Scrooge and Cratchit is great enough to trigger an entitlement on Cratchit’s part to some portion of Scrooge’s resources. Several difficulties immediately arise.
First, if Cratchit was initially as wealthy as Scrooge, and through some misfortune has become poor overnight, then Scrooge, through no action of his own, has unwittingly passed from rightful possession to wrongful possession of the resources in question. If seizing resources is to count as force, as it must if property rights are to be based on the right not to be aggressed against, then from Cratchit’s suddenly acquiring title to (and thus a right to seize) these resources in Scrooge’s possession, it follows that Scrooge’s possession of them must suddenly have come to count as aggression (since otherwise Cratchit’s seizure of the resources would be initiatory force). But any conception of aggression according to which one can become an aggressor merely by undergoing a Cambridge change seems inadequate. 
Moreover, how great must the disparity of wealth between Scrooge and Cratchit be before the transfer of property rights is triggered? To what percentage of Scrooge’s resources does Cratchit become entitled? If there are many Scrooges and many Cratchits, by what means are we determine how much which Cratchits may take from which Scrooges? The Rawlsian Difference Principle and other such guidelines would be of little help here, for they specify no determinate outcome; one cannot say, e.g., that any given Cratchit has a right to keep seizing resources from any given Scrooge until the disparity in their respective socioeconomic conditions is reduced to a point that is favorable to the worst-off person, for that yields no concrete guidance. The Difference Principle is not meant to be a policy dictating specific transfers; rather, it is a standard against which policies dictating specific transfers may be tested.
More precisely, the Difference Principle and other such guidelines are not principles of interpersonal ethics; rather, they are meant to guide the laws and policies of a political regime. What the welfare-statist is really advocating is not Cratchit’s right to seize some portion of Scrooge’s resources, but Cratchit’s right to have the government allocate resources in accordance with rules that pass the test of the Difference Principle or some analogous principle. But now it is the government’s right to control Scrooge’s resources that stands in need of justification. 
Since governments, on any liberal view, are not mystical bodies of social union but are simply collections of individuals, on an equal moral footing with the individuals they govern, a government can have no rights in excess of the sum of the rights of the individuals composing it. 
Recall, too, that if rights are to serve as an external standard for the evaluation of political institutions, they cannot without circularity be defined in terms of such institutions; on the contrary, to paraphrase Jefferson, governments are instituted among men to secure rights independently defined. Hence there cannot be a basic right to be treated in a certain way by government; any such right must be reducible to rights holding in ordinary interpersonal relations. The libertarian system of property rights is specifiable in such terms; the welfare-statist one, it seems, is not.
Of course, just as it is open to the welfare-statist to reject the Positive Thesis that people have a right not to be aggressed against, it is also open to the welfare-statist to reject the claim that rights are an external constraint on political institutions. I submit, however, that the result will not only no longer be libertarian; it will also no longer even be liberal. 
The truth or falsity of libertarianism, however, is not my present concern. I claim to have shown only the following:
- Whether or not the Positive Thesis, that we have a right not to be aggressed against, is true, there is certainly nothing mysterious or one-sided about finding such a thesis plausible and attractive.
- Given the Positive Thesis, together with some highly plausible auxiliary premises, the Negative Thesis, that we have no rights other then the right not to be aggressed against, necessarily follows, and so there is nothing mysterious or one-sided in embracing it.
- Given the Positive and Negative Theses, the libertarian view of property rights is more defensible than the welfare-statist view, and so there is nothing mysterious or one-sided about preferring the former to the latter.
To the extent that I have succeeded in my purpose, the libertarian’s ethical and political commitments should now be, if not compelling, then at least comprehensible. 
1. Don Herzog, “Gimme That Old-Time Religion,” Critical Review 4, nos. 1-2 (1990), pp. 74-85.
2. In light of the diversity of the libertarian movement, there is probably no true sentence beginning with “Libertarians believe,” if that is read as “All libertarians believe”; but the view described here is certainly the dominant one. Hence the term “libertarians,” here and throughout, means no more than “the libertarian mainstream.” A typical statement of the kind of position I describe, though differing in presentation from my account, is Murray N. Rothbard, The Ethics of Liberty (New York: New York University Press, 1998).
3. It should be noted that “aggression,” as used here, is a descriptive concept, not a normative one; hence the libertarian prohibition on aggression is not a truism. (Admittedly, the term “aggression” has pejorative connotations – and deservedly so! But so do terms like “torture” and “genocide”; that doesn’t make them normative concepts. In such cases, the pejorative connotation is not part of the stipulated meaning of the term, but derives from the recognition that what the term describes is in fact evil.)
4. My own position is that deontological considerations ground a strong presumption in favour of the Positive Thesis; that this presumption could in principle be overridden by sufficiently weighty consequentialist considerations; and that, nonetheless, consequentialist considerations in fact reinforce the Positive Thesis rather than overriding it.
5. This is true even of that minority of libertarians that bases libertarian rights on an egoistic foundation. Ethical egoism is a theory not of the scope of our obligations, but of their ground.
6. For the libertarian, of course, one’s property includes not just external resources but one’s own person as well; but for present purposes I shall ignore this complication and restrict the use of the term “property” to external resources.
7. It’s worth noting that most libertarians regard the actual operation of the regulatory welfare state as, on balance, upwardly rather than downwardly redistributive – a claim supported by appeal to economic and historical considerations, and often invoked in consequentialist arguments for the Positive Thesis; see, e.g., Roderick T. Long, “Rothbard’s ‘Left and Right’: Forty Years Later,” Mises Daily Article, 8 April 2006, <http://mises.org/story/2099>; “They Saw It Coming: The 19th -Century Libertarian Critique of Fascism,” 2 November 2005, <http://lewrockwell.com/long/long15.html>; and “Who’s the Scrooge? Libertarians and Compassion,” Formulations 1, no. 2 (Winter 1993-94), <http://tinyurl.com/7pqhr>.
8. See Roderick T. Long, “Abortion, Abandonment, and Positive Rights: The Limits of Compulsory Altruism,” Social Philosophy and Policy 10, no. 1 (1993), pp. 166-91.
9. Or as compensation to the victim of a rights-violation; for an account of this right as an application of, rather than a supplement to, the right not to be aggressed against, see Roderick T. Long, “The Irrelevance of Responsibility,” Social Philosophy and Policy 16, no. 2 (1999), pp. 118-145.
10. cf. James P. Sterba, “From Liberty to Welfare,” Social Theory and Practice 11, no. 3 (1985), pp. 285-305.
11. Recall that aggression is still being treated as a descriptive concept, not a normative one. Hence the question is not whether the grab-what-you-can world is free of injustice, but whether it is free of initiatory force. If I starve to death because someone raids my food stores every time I turn my back, it does not seem implausible to describe the situation as one in which I am forced into starvation.
12. Robert Nozick, Anarchy, State, and Utopia (New York: Basic Books, 1974).
13. To say that nobody is entitled to the resource is self-defeating, since that would mean that nobody has a right to decide what happens to it, which in turn would mean that nobody has a right to interfere with anybody else’s use of it – which comes perilously close to conceding title to whichever person is using it at the moment.
14. I am sympathetic to a broadly Lockean account in which a person’s right to exclusive control over her possessions is seen as closely analogous to her right to exclusive control over the molecules currently composing her body. In effect, the physical boundaries of the self are not one’s body but one’s ongoing projects; indeed, a person’s body just is one of her ongoing projects, so the right to bodily integrity is just one more property right. (cf. Samuel C. Wheeler III, “Natural Property Rights As Body Rights,” Noûs 16 (1980), pp. 171-193.) However, I do not take my present argument to depend on the correctness of this account, since at the moment my thesis is not that the libertarian view of property is true, but rather that it is, while the welfare-statist view is not, intelligible as an application of the Positive Thesis.
15. Ann Levey suggests that a welfare-statist could evade my Cambridge-change objection by claiming that no one has a right to any property above a basic minimum; in that case, the surplus property rights of the wealthy, rather than having Cambridge changes as their transfer conditions, would never exist in the first place. This would of course be a rather odd welfare state; once everyone had received the basic minimum, the government could freely grab the surplus of the wealthy, and the wealthy could freely grab it back. But such a system, even if workable, is still vulnerable to a Cambridge-change objection. There cannot be a rights-violation without a rights-violator; so if I have a right to a basic minimum, that means that when I fall below that minimum, someone must be violating my right. But if everyone were to fall below the basic minimum, then no one could count as the rights-violator. Hence the right to a basic minimum makes sense only if the level of the basic minimum is not fixed, but varies with the general affluence of society. But in that case, we still get the Cambridge-change problem: whether I count as an aggressor or not will depend on changes elsewhere in the economy.
16. James Sterba argues that welfare rights are negative property rights, and infers that libertarian considerations therefore mandate a welfare state: “Only a welfare state would be able to effectively solve the large-scale coordination problem necessitated by the provision of welfare. Consequently, once a system of welfare rights can be seen to have a libertarian justification, the argument for a welfare state hardly seems to need stating.” (Sterba, op. cit., p. 305.) But even if we leave aside the consequentialist arguments offered by libertarians against the thesis that the welfare state is the most effective means of securing welfare rights, there is still a problem: if, as Sterba seems to see, it is only in the context of a welfare state that it can be settled which obligations are entailed by welfare rights, then pre-existing welfare rights cannot, contra Sterba, be given any specificity, and so cannot be used to justify the establishment of a welfare state in the first place. (But for a possibly contrary view see Jeremy Shearmur, “The Right to Subsistence in a ‘Lockean’ State of Nature,” Southern Journal of Philosophy 27, no. 4 (1989), pp. 561-68.)
17. For the basically egalitarian impulse behind libertarian doctrine, see Roderick T. Long, “Equality: The Unknown Ideal,” <http://www.mises.org/story/804>.
18. cf. Roderick T. Long, “Immanent Liberalism: The Politics of Mutual Consent,” Social Philosophy and Policy 12, no. 2 (1995), pp. 1-31.
19. This paper has benefited from helpful comments by Ann Levey – though I suspect she will find this version as deranged as the last one.