That leaves me with (d), which I will try. Not, however, with any great originality. In short form, I think libertarianism aims at something like the Kantian kingdom of ends. In what follows, I will explain how I think this works. If needed, I will answer questions and objections in a future post. We all know they’re out there.
2. Who We Are
As with people in general, we can split libertarians into two camps, God and no‐God. I’m in the no‐God camp, although my reasons are outside the scope of both this essay and this website.
Is nothing sacred to me? On the contrary, many things are. The very first among these — the first by a long, long way — is the human mind. Why? Because it is the only part of the cosmos, so far as we know it, that is able to understand, to reason, to conceive of plans, to execute those plans, and thereby to improve both itself and its circumstances, according to its own judgment.
The mind’s reasoning power means that nothing is more fascinating, nothing more triumphant, nothing more holy in all the universe. Nothing else appears even to come close.
This fact has consequences.
Were there only one human being, and assuming him or her to be of good character, I would want that person to claim title to the whole universe, to enjoy it to the fullest possible extent, and to gather every natural advantage that might be found in it. I would want that person to be emperor of the universe.
We are simply that great. We are so amazing, in fact, that we have literally no idea how far we’ll go or what lies in store for us as a species. My bet though is that it’s wonderful. All because of the individual mind.
And yet — there are billions of us. And we all have minds. This fact too has consequences.
Whatever abstract rules I would set up for myself, I must hold out for you as well. All of you, equally. You may differ in your capacities, and obviously you do, but you all very clearly stand in the same relationship to one another and to the rest of the universe that I do. You are all reasoners, and to the extent that I respect reasoning powers in myself, so too I must respect them in you.
No, solipsism isn’t a way out. I couldn’t adopt solipsism without doing significant violence to my own reasoning power in the process. So I’m stuck with you. And you? You’re stuck with me, by exactly the same token.
But how does one ethically govern a planet full of such wonderfully dignified creatures? There are only so many possibilities:
We can’t all be universal emperors simultaneously and in the same respects. Conflicts would arise immediately over scarce or unique resources, and these would admit of no resolution.
Violence doesn’t help. It would be wrong to inflict harm on someone of an equal dignity to myself, merely to gain what would be for me at best a means to an end. I must act according to a law that treats like cases alike, and thus I must forebear. And so must you.
We can’t hold everything in common. The decisionmaking would be too cumbersome, and we would rarely if ever achieve consensus. Knowledge problems would arise. And with common ownership, the incentives for dishonesty and irresponsibility would multiply.
No, elitism isn’t a way out. Giving greater worth or dignity to a select few is tempting — tremendously, for some — but the society that adopts the rule of the greatest sooner or later ends in the rule of the most vicious.
And so, whenever possible, we make sure that no one rules over anyone but themselves.
We insist on liberty because it is the only approach to politics that consistently attempts to treat people as ends in themselves, not as the means to some other end. Command‐based political orders all violate the categorical imperative. They all use some human beings merely as tools for the purposes of some other human beings.
The system of natural liberty is at the very least trying mightily to avoid that outcome. This is what I take Robert Nozick to have meant with his defense of rights as side constraints and his invocation of Kant in Anarchy, State, and Utopia:
Side constraints upon action reflect the underlying Kantian principle that individuals are ends and not merely means; they may not be sacrificed or used for the achieving of other ends without their consent… Side constraints express the inviolability of other persons. But why may not one violate persons for the greater social good? [Because] there is no social entity with a good that undergoes some sacrifice for its own good. There are only individual people, different individual people, with their own individual lives. Using one of these people for the benefit of others uses him and benefits the others. Nothing more.
Nozick admits that adding enough side constraints to leave people complete self‐rulers could be an “impossibly stringent condition,” but he does give the side constraint against aggression a strong philosophical grounding, and he demonstrates that it leads to very familiar libertarian conclusions: Kantians should be libertarians, or else something a whole lot like us.
Whether we can perfect Nozick’s “impossibly stringent” set of side constraints and achieve complete self‐rulership is immaterial. To the extent that a free and equal liberty can be realized for all, it should be. In Herbert Spencer’s words, “[E]very man may claim the fullest liberty to exercise his faculties compatible with the possession of the like liberty by every other man.”
3. Why We Do Markets
“Yeah, but wait,” someone might say. “I thought you promised me the universe!”
I did. But only if you were all alone. Now, I trust that you probably wouldn’t want to be, and anyway, getting there from here would break the constraints we’ve just so carefully set up.
We can, however, do something a lot like giving everyone the universe: We can increase the stock of available goods, both in their quantity and in their quality, and we can distribute them efficiently. We do this through markets.
Indeed, living in a market order is to my mind clearly better than possessing the whole universe all alone. Markets mean more and better food. Markets mean books, and effective medicine, and music, and beer. I am unlikely to ever produce these things all by myself — or if I did, I would have to neglect many other things, and then I’d die from lack of them. Although I’m not exactly making the case in a rigorous way, it seems clear to me that that man the reasoning animal deserves not the whole universe to himself, but rather a society of similar beings. They are not a problem or an obstacle, but a distinct improvement over isolation.
We do markets because beings like us deserve the array of helps and enhancements that only systems with a significant market component can offer. Markets allow us to create a better world, and they reward us both directly, in the form of compensation for work, and indirectly, in the growing menu of goods and services we can choose from.
Most importantly, nothing about the market process properly considered violates our side constraints. This is what makes markets not simply advantageous, but morally permissible.
It is sometimes objected, when I have spoken favorably of the categorical imperative as a foundation for libertarian political theory, that this principle would forbid all market exchanges: Doesn’t the buyer use the seller as a means, and vice versa?
The answer is no. In a voluntary market exchange, buyer and seller formulate a plan together — a plan to redistribute limited amounts of money, goods, and/or services. These things are the tools being used, not the individuals.
The plan also functions as a means for them both, one that aims at the end of individual betterment, not for one person, but for two: I get bread, so I live a bit better; the baker gets money, so his bakery does well, and he lives a bit better too. Could I will that everyone proceeded along such lines? Of course I could, and I do.
4. Down with the Non‐Aggression Axiom, Up with the Non‐Aggression Presumption
What though about the non‐aggression principle? Certain of Zwolinski’s criticisms still seem to me to miss the mark. This appears especially true of the claim that the non‐aggression principle is “parasitical” on a theory of property.
Well, what if it is?
Consider that the vast majority of the world’s religions are also parasitical on a theory of property: Whenever a religion has declared “Thou shalt not steal,” that pronouncement has depended on contingent, changing, history‐bound, human‐made definitions of “stealing.”
Did the Almighty or his spokespeople — in Judaism, Christianity, Islam, Hinduism, Buddhism, Confucianism, and many others — just happen to overlook the fact that they weren’t supplying a theory of property rights, but merely piggybacking on one already in place?
No. They knew of and were wholly untroubled by this move. If we suppose God to have been the author of any of these systems, then He obviously wasn’t bothered. If we suppose the systems to be of human creation, the human authors appear equally unruffled.
Can Zwolinski really have been the first to notice this problem? (The first, perhaps, outside of Karl Marx?) I don’t think so. Much more likely is that’s not really a problem at all.
Without meaning to endorse any particular culture’s theory of property, and still less any particular religion, I note that it was commonly the intent of the world’s religious traditions to ratify something like the status quo in property rights, whatever that status quo may have been in a given time or place. (Recall that that status quo may have been bad: in slave societies, “thou shalt not steal” has perverse consequences, in that it condemns the liberator of slaves.)
So yes, the non‐aggression principle is parasitical on a theory of property — but which theory is it? Happily, the answer in our particular historical moment is both obvious and good.
In the Anglo‐American world one theory of property is so well ratified by time and experience that it hardly needs much defense outside of an academic philosophy department. Roughly, property is possessed by individuals — by persons, under the law. Justice in holdings is validated by looking at the history of an item’s acquisition, alienation, and reparation, and by establishing factual claims about various events from that history. It is presumed that real and personal property can be bought and sold with a minimum of encumbrance unless specified otherwise, and that such transactions work a permanent change in ownership, again unless specified otherwise — in which case, we speak not of a sale, but of a lease or a rental agreement. These are separate matters in the law.
Reference to this theory of property allows us to do markets. It gets us to a peaceful way of allocating real and personal property in a way that tends to benefit those who work within it honestly. It also solves a whole lot of conflicts before they even get started.
To say that initiating physical force against someone is justified only if he or she violates this complex set of norms is itself a complex claim. By the same token, though, it’s not a vacuous claim, not a tautology, and not at all impossible to apply. On the contrary, applying it consistently will get us something a lot like a viable libertarianism.
(Its application will, however, necessarily give rise to disputes over particular matters. That’s exactly what property law does. To think that all disputes in a social order as complex as the law of property might be settled by an axiom is to misunderstand the nature of the legal order.)
But also: in the language of ethics, the non‐aggression principle is not a categorical imperative. It’s not a principle to apply in all times and all places, without qualification. It is a hypothetical imperative — a principle to be applied only if certain circumstances arise. In those circumstances, good things on the whole tend to result from acting on this principle.
Yet the discovery that a particular system of political or ethical obligations usually has good consequences does not establish it as a categorical imperative. A categorical imperative can only come from considerations about one’s own nature, considerations about the like nature of others, and the consequences that follow necessarily from the two.
And so, in those rare circumstances where observing the non‐aggression principle means that someone is treated merely as the means to some other end, we should abandon it in favor of respect for persons as ends in themselves.
Consider the case of the man who has fallen out the window of a high‐rise apartment and caught hold of the flagpole one story below. His neighbor below forbids all trespassing, even to save a life. “It’s my property,” he says, “and that’s all that matters. Now, you may hang there until your arm gives out, but I will give you no help.”
Were the non‐aggression principle axiomatic, we would have no recourse here. But consider: Could we will that everyone behaved likewise? Does it show respect for persons? Isn’t it clear that a person’s life is being treated as worth rather less than a few footprints on a carpet?
The neighbor’s behavior is appalling, and to will its maxim as a universal law would be tantamount to setting up a lottery, in which the unlucky were always permitted, even required, to die for the edification of the lucky, if the latter so chose. If we knew this from the outset and willed it anyway, then we would will that some people would (though rarely) be used merely as means to an end. This we have forbidden.
That said, we might still object that the state has no power to intervene. As we all know, some moral lapses aren’t properly subject to law, and this might be one of them. Then we should ask: could we will thatthe maxim behind intervention become universal law? The maxim that says it is okay to trespass, even forcibly, to save a life, particularly if the consequences of the trespass are trivial?
That seems fine to me. I don’t at any rate see atrocities coming out of it, not in the way that I do with the only other alternative. The non‐aggression presumption has been defeated. Break down the neighbor’s door, open the window, and save the falling man’s life. Compensate the neighbor afterward. (Note that trespass can be compensated to the sufferer; death cannot. This may also be a relevant consideration.)
Respect for property is indeed somewhat weakened, but respect for human life is strengthened. Property is a means to an end, and that end is nothing other than human life, with all of us considered as individuals and moral equals, and none merely as a means to an end.
Does the example yield enforceable positive interpersonal obligations? Yes it does, but only some quite trivial ones for the temporary use of property, and then only owing to some very unusual physical and moral circumstances. A left‐liberal who was also ethically a Kantian might argue that the class of similar cases is on the contrary very large, but we need not agree with this claim, particularly when we consider the ways in which state interventions tend to use individuals directly and blatantly as the means toward other individuals’ ends.
So we strike a bargain: We admit that in an exceptionally rare set of circumstances and perhaps a few others like it, we will violate the non‐aggression principle in consideration of a higher end. That higher end will if properly considered return us directly to respect for property in all other circumstances. In return for this concession, we re‐connect libertarian political theory to its own rich and profound history — re‐connect it to Hume, Kant, Spencer, Hayek, and many of the rest of the classical liberals.
That seems like a good bargain to me.
 Robert Nozick. Anarchy, State, and Utopia. New York: Basic Books, 1974, pp 30–33.