Natural Law Theory, Consequentialism, and Argumentation Ethics: A Response to Olav Dirkmaat

Natural Law Theory, Consequentialism, and Argumentation Ethics: A Response to Olav Dirkmaat

Martín C. Gamazo

July 3, 2026

Property and Freedom Journal

Olav Dirkmaat recently published an article comparing natural law theory (iusnaturalismo) with consequentialism, arguing that the former is mistaken and the latter is the correct way to justify libertarianism.^[1] In this response, we will set aside several problems with the article, such as the fact that at no point does it present, even in summary form, a libertarian natural-law theory, such as the one developed by Murray Rothbard.^[2] We will focus on two aspects of his article: his justification of consequentialism and his critique of Hans-Hermann Hoppe’s Argumentation Ethics.

In his article, Dirkmaat states the following:

The only definitive answer to the question of whether a set of rules produces good or bad consequences is offered by the long-term survival of the collective […] Rule consequentialism must be a principle of civilizational preservation, where the continuity of society depends on the collective capacity to create wealth.^[3]

This claim by Dirkmaat, which seems fairly sensible, has an important problem. Indeed, Dirkmaat offers no argument to justify why “civilizational preservation” is something positive capable of grounding an ethical or moral theory. By asserting that this is a positive consequence and using it as the foundation of his consequentialism, he is issuing a positive value judgment about that consequence, but he does not explain why society should be oriented toward achieving such an end. Who is Dirkmaat to impose his positive value judgment about civilizational preservation on the rest of the individuals in society? Dirkmaat seems to implicitly assume that the preservation of civilization is an end common to all of humanity.^[4] However, this is completely false. To begin with, how can Dirkmaat know the preferences and ends of all of humanity? Thanks to praxeology, it has been shown that the only preferences of other individuals that a social scientist can know are demonstrated preferences—that is, one can only observe what an individual preferred in the past through their past actions.^[5] However, by observing individuals’ past actions, one can hardly conclude that they desire the preservation of civilization, especially when hedonistic behaviors are observed. Indeed, what happens in a society full of hedonistic individuals who prefer to maximize their present satisfaction at the expense of civilization’s future? And what if this hedonism entails satisfaction through interventionist measures? Or, what happens if the individuals of a society perceive socialism as just, regardless of whether it can preserve civilization, with justice being their highest-priority end? There is no way Dirkmaat’s rule consequentialism could justify libertarianism in any of these contexts.

Dirkmaat might claim that such societies would eventually perish, and that only societies which save, accumulate capital, and adopt more liberal^[6] measures will survive. In this way, his rule consequentialism would not need to justify itself in hedonistic societies, and would simply end up prevailing. However, here Dirkmaat falls into contradiction with a claim he makes later on. Indeed, according to Dirkmaat, “It is not always clear what the evolutionary process is aiming at—that is, the selection criterion—and this is something we cannot establish a priori.”^[7] If this is true, then a) we cannot know that his rule consequentialism will prevail in the long run, and b) we do not know which societies will survive. At present, every major nation has an enormous welfare state. Given this claim of Dirkmaat’s, we cannot know whether these societies, as they currently exist, will survive the evolutionary process—and therefore his rule consequentialism cannot be justified in them. From this evolutionary perspective, how can Dirkmaat oppose the welfare state at all?^[8]

But there is also another possible scenario in which a society that does not follow a liberal or libertarian morality would preserve itself over the long term and survive the evolutionary process. Let us take an example Rothbard used to critique utilitarianism and adapt it to our present discussion.^[9] Suppose a society is deeply convinced that redheads are a danger to civilization, and that, in order to preserve civilization, it is necessary to kill all redheads. Suppose, further, that this society is a saving society with a deeply liberal economic policy. This society would survive the evolutionary process thanks to its liberal economic policy and its saving population. Yet nothing would stop the members of this society—and of others wishing to imitate it—from attributing its success to the genocide of redheads, so that every society wishing to preserve itself would begin hunting redheads. Dirkmaat might respond that economic science can demonstrate that the preservation of that civilization is due to its economic liberalism and its saving population, and certainly not to the genocide of redheads, and that this would be shown evolutionarily once societies that carry out the redhead genocide without economic liberalism perish, or once societies that apply liberalism without the redhead genocide survive. This would, again, contradict his claim on the impossibility of knowing a priori what the evolutionary process aims at. We will, however, ignore this for the sake of the argument. What happens if, within the society described above, a religion arises that preaches the genocide of redheads, and most or all of the population adheres to it? So long as this society remains a saving society with a liberal economic policy, it will certainly survive. How, with his simple rule consequentialism, does Dirkmaat defend the lives of redheads? Without an ethical or legal theory demonstrating that it is always unjust and immoral to take an innocent life, and that also correctly establishes what it means to be innocent (otherwise, having red hair could be considered a crime, and redheads would therefore not be innocent), it is simply impossible to defend the right of property over one’s own body (which is what the right to life entails) or the right to private property.

But Dirkmaat not only offers a poor justification of his consequentialism—his attack on Hoppe’s Argumentation Ethics is also a straw man, since he does not bother either to reconstruct Hoppe’s argument or to refute it. Dirkmaat simply cites Jason Brennan’s critique,^[10] a critique which, incidentally, is not rigorous at all and likewise does not bother to reconstruct Hoppe’s argument. Let us now briefly reconstruct Hoppe’s argument, so as to then examine the criticisms made by Brennan that Dirkmaat defends.^[11]

Before continuing, let us briefly define certain important terms used in the following discussion, so as to avoid possible misunderstandings: property, aggression, conflict, and argumentation. Property is an individual’s right to exclude others from the use of a scarce good.^[12] Aggression is defined as the initiation of the use of physical force, or the threat of the initiation of physical force, against another individual’s property without their prior consent. Conflict arises when two or more people have incompatible claims over the control or use of the same scarce good. Argumentation is a propositional exchange between two or more individuals, free of conflict,^[13] aimed at demonstrating the truth or falsehood of a proposition or to find a solution to a practical problem.

Hoppe begins by demonstrating that every truth-claim must be justified argumentatively. Indeed, to deny this is to argue the contrary, and is therefore a performative contradiction. Furthermore, since argumentation is a practical activity, and not merely floating propositions, it requires presupposing certain norms that make argumentation possible. If argumentation requires presupposing certain norms, then one cannot argue against them, since doing so would entail a performative contradiction (it would be equivalent to my arguing that I do not exist, when my existence is precisely what makes argumentation possible). Everything that argumentation presupposes in order to be possible we call the a priori of argumentation.

The norms presupposed by argumentation must then be universalizable. Indeed, argumentation presupposes that everyone capable of understanding it must be able to be convinced by the argument alone, so the principles argued for must be valid for everyone without exception. However, universalizability is not the only normative criterion that argumentation presupposes.

In addition, the norms presupposed by argumentation must allow for the survival of individuals. Indeed, if a norm does not allow for the survival of individuals, then argumentation would never be possible. To argue presupposes that the individuals participating in it are alive, and therefore no norm that inevitably leads to death can be justified.

Recall that argumentation is a conflict-free activity, and is therefore incompatible with any norm that fails to avoid conflict. Moreover, the very purpose of any ethical norm is to avoid conflict, so any norm that fails to do so contradicts its own purpose. Furthermore, argumentation, being a practical activity, requires the use of at least one scarce good: one’s own body. Since each individual has direct control over their own body, and such direct control cannot be transferred, any individual can control another individual’s body only indirectly. Moreover, a norm implying that some individuals control both their own body and that of others, while others control neither their own nor anyone else’s, not only fails to avoid conflict but is also not universalizable, and therefore cannot be justified argumentatively. The other possibility is that everyone owns everyone’s body. This norm certainly passes the universalizability test. However, first, it does not avoid conflict. Second, this norm would imply that, for any individual to act, they would need to ask permission from every other individual in order to act and make use of their body. However, simply asking permission requires the use of one’s own body, so no individual could do anything at all, and as a result everyone would die. This norm does not allow for survival and therefore cannot be justified argumentatively either. The only norm concerning the body that remains justifiable is that each person owns their own body, and that no one has the right to aggress against another individual’s body. This is the only norm regarding bodily use that avoids conflict, is universalizable, and allows for the survival of humanity, and it forms part of the a priori of argumentation.

Once it has been established that the only justifiable norm regarding bodily use is each individual’s ownership of their own body, what remains to be resolved is the matter of external goods. First of all, to claim that some individuals may appropriate goods while others may not fails the universalizability test and is therefore not justifiable. Another possibility would be that no one owns anything. However, if no one could appropriate anything, then a) everyone would cease to exist, since appropriating at least certain goods is necessary for survival, and b) the claim that no one can appropriate anything implies that everyone has the right to exclude everyone else from the use of all goods—so the claim that no one can appropriate anything necessarily implies another possible norm: that everyone owns everything, meaning one cannot justify the existence of scarce goods that are unownable. However, everyone owning everything implies that no one has the right to use a scarce good without everyone else’s permission. Therefore, everyone’s permission would be required to use any good at all. But simply asking for permission requires the use of scarce goods, if only to survive, so such a norm is also unjustifiable: everyone would die, and argumentation would not even be possible. This impossibility becomes even more pronounced if we count future generations among the legitimate owners, since it would then require the permission of people not yet even conceived—though the impossibility holds even without considering future generations. Another possible norm would be that anyone, regardless of whether someone was there before or used a good previously, could appropriate something by decree. This norm has two problems. First, it would also imply that, in using a good, an individual is using the legitimate property of someone else—someone perhaps not yet born—so that the use of any scarce good whatsoever would be impossible, and everyone would cease to exist. Second, this would imply that anyone could appropriate another person’s body by decree, which, as we saw, is unjustifiable, since it fails to avoid conflict, and the absence of conflict is a necessary precondition for argumentation. Likewise, it would imply conflict between whoever appropriated a good first and whoever came later to try to appropriate it. As we can see, there is no way to justify such a norm. Only one possible norm remains: original appropriation, production, and voluntary exchange. This means that an individual can appropriate a good that no one has appropriated before them by working it—or, more precisely, by working or creating intersubjectively and objectively recognizable “boundaries” in a good so as to demonstrate that the individual in question has appropriated it. Furthermore, these previously appropriated goods can be used to produce other goods, of which the individual would likewise be the owner, and all ownership of goods external to the body can be transferred through voluntary contracts (ownership of one’s own body cannot be transferred, since it is impossible to cede direct control over it, and ceding indirect control would mean that conflict could arise between whoever controls the body directly and whoever controls it indirectly).^[14] This norm is universalizable, allows for the survival of humanity, and also allows conflict to be avoided. It is therefore the only norm that does not contradict the a priori of argumentation, and the only one justifiable argumentatively.

We have finished reconstructing Hoppe’s argument. Let us now examine the arguments of Brennan’s that Dirkmaat refers to—though not before offering a brief critical comment on one of Dirkmaat’s claims.

Dirkmaat mentions Argumentation Ethics when discussing natural law theory, without drawing any distinction. While it is true that Hoppe himself mentioned that Argumentation Ethics could be interpreted as a rightly understood natural law theory, he also distances it from that tradition, since it does not proceed from the broad notion of “human nature,” but from something much narrower and more precise: argumentation.^[15] This might lead a reader unfamiliar with Hoppe’s work to think that Dirkmaat’s critique of natural law theory—regarding the unintelligibility of the human nature from which it proceeds—also applies to Argumentation Ethics, which is completely false. I do not know whether such an omission on Dirkmaat’s part is due to carelessness, an ill-intentioned lack of intellectual honesty, or ignorance of what is being criticized (which would likewise entail intellectual dishonesty).

Now, let us examine Brennan’s arguments. Brennan begins by distinguishing “liberty rights” from “claim rights.” He defines the former as “something that grants me permission to do something.” and the latter as “something that entails others have obligations, responsibilities, or duties toward me.”^[16] Brennan claims that the libertarian right of property over one’s own body corresponds to a claim right. He then argues that the fact that argumentation presupposes the use of one’s own body only shows that one cannot argue against the liberty right to use one’s own body, but in no way presupposes the claim right of ownership over one’s own body. In this way, Brennan claims, Argumentation Ethics fails to justify libertarian property rights.

We may now turn to examining the fallacies Brennan falls into in his critique of Hoppe’s argument. First of all, it is important to nuance Brennan’s characterization of libertarian property rights as claim rights. Indeed, libertarian property rights do not entail a positive obligation or duty between individuals, but a negative one. That is, they do not obligate anyone to perform a given action, but rather not to perform actions that violate other individuals’ property rights. Then, according to Brennan, a liberty right means that whoever holds it is entitled to perform an action. For someone to have the right to perform an action means that no one else has the right to prevent them from doing so. Thus, if it is shown that argumentation presupposes the liberty right of ownership over one’s own body,^[17] then argumentation presupposes that no one has the right to interfere with property rights over one’s own body—thereby successfully justifying libertarian property rights.

Beyond this, Argumentation Ethics does not merely justify a liberty right on the grounds that argumentation presupposes the use of one’s own body. Argumentation Ethics demonstrates that each individual’s ownership of their own body is a norm that argumentation presupposes, since argumentation is a practical activity that presupposes the absence of conflict, and the only way for conflict to be avoided is by presupposing this norm. In this way, what Argumentation Ethics justifies is that nothing which violates this norm can be justified argumentatively. This exposes Brennan’s entire critique as a mere straw man, made possible only because he does not bother to reconstruct Hoppe’s argument before criticizing it.

It is no surprise that an article of such little seriousness—one that claims to refute something like Argumentation Ethics in 60 seconds—contains nothing but fallacies. It is likely for this same reason that Dirkmaat did not properly cite Brennan’s article, nor bothered to explain the critique, merely mentioning that Brennan refutes Hoppe’s argument and quoting Brennan’s conclusions.

As a brief note, Dirkmaat’s claim about the incompatibility of natural law theory (and of Argumentation Ethics) with spontaneous order is true, but not for the reasons Dirkmaat believes. The claim is true because the theory of “spontaneous order” is itself untenable. The problem is not natural law theory (at least when properly understood, through Argumentation Ethics), but rather the irrational idea of spontaneous order. In fact, Hoppe himself has already undertaken to refute Hayek on this very subject.^[18] I do not intend to elaborate much on this topic here, since it is not the subject of Dirkmaat’s article and I am currently preparing an extended essay on Hayek, but it was worth noting.

If one is going to attack an argument, it must be done honestly and coherently, not through fallacies, and if one proposes a theory, it must be rigorously justified. Dirkmaat fails spectacularly at both tasks.

Endnotes

[Ed. note: For further resources, see Stephan Kinsella, “Argumentation Ethics and Liberty: A Concise Guide” (2011) and Supplemental Resources,” StephanKinsella.com (Jan. 1, 2015).]

^[1] See Olav Dirkmaat, “Iusnaturalismo versus consecuencialismo: por qué el derecho natural es incompatible con el orden espontáneo.” CADEP, June 16, 2026. https://cadep.ufm.edu/iusnaturalismo-versus-consecuencialismo/.

^[2] See Murray N. Rothbard, The Ethics of Liberty, intro. Hans-Hermann Hoppe (New York: NYU Press, 2015 [1982]), pp. 3–26.

^[3] Dirkmaat, “Iusnaturalismo versus consecuencialismo”. Translation by me.

^[4] In this sense, Dirkmaat’s proposal is very similar to Ludwig von Mises’s “rightly understood interests.” See Ludwig von Mises, Human Action, Scholar’s ed. (Auburn, Ala.: Mises Institute, 1998 [1949]), pp. 669–678. For a critique of Mises’s “rightly understood interests,” see Murray Rothbard, The Ethics of Liberty, pp. 208–209.

^[5] See Murray N. Rothbard, “Toward a Reconstruction of Utility and Welfare Economics”, reprinted as chapter 17 in idem, Economic Controversies (Auburn, Ala.: Mises Institute, 2011), pp. 289-333.

^[6] Here we use “liberal” in the classical European sense.

^[7] Dirkmaat, “Iusnaturalismo versus consecuencialismo”. Translation by me.

^[8] An excellent critique of this irrational Hayekian evolutionism that Dirkmaat adopts can be found in Hans-Hermann Hoppe, “Hayek on Government and Social Evolution,” reprinted as chapter 22 in idem, The Great Fiction: Property, Economy, Society, and the Politics of Decline, 2nd expanded ed. (Auburn, Ala.: Mises Institute, 2021), pp. 403–432.

^[9] Murray Rothbard, The Ethics of Liberty, pp. 201–202 and p. 213.

^[10] Jason Brennan, “Hoppe’s Argumentation Ethics Argument Refuted in Under 60 Seconds,” Bleeding Heart Libertarians, December 12, 2013. https://bleedingheartlibertarians.com/2013/12/hoppes-argumentation-ethics-argument-refuted-in-under-60-seconds/

^[11] This reconstruction is based mainly on what, in my opinion, is the best and most complete exposition of Argumentation Ethics, found in Hans-Hermann Hoppe, A Theory of Socialism and Capitalism: Economics, Politics, and Ethics, 2nd ed. (Auburn, Ala.: Mises Institute, 2016 [1989]), chapter 7, pp. 145–165, and draws on certain clarifications made by Stephan Kinsella in Kinsella, Legal Foundations of a Free Society (Houston, TX: Papinian Press, 2023). Kinsella has proposed his own approach to justifying libertarian property rights: Estoppel. I consider the argument correct and complementary to Argumentation Ethics. However, we decided not to present it here since it is not the subject of Dirkmaat/Brennan’s criticisms.

^[12] Stephan Kinsella has proposed the adjective “conflictable” as much better suited to expressing the idea we are trying to convey when speaking of a scarce good. I fully agree with Kinsella’s proposal, but for the sake of simplicity and space, decided to retain the more traditional adjective “scarce.” See Stephan Kinsella, “On Conflictability and Conflictable Resources,” StephanKinsella.com (Jan. 31, 2022).

^[13] Here we use “free of conflict” not in the sense that there is no disagreement, but in the sense that the participants in the argumentation can at least agree that there is disagreement.

^[14] On why ownership of one’s own body cannot be transferred, see Kinsella, Legal Foundations of a Free Society, chapter 11, pp. 263–281.

^[15] Hoppe, A Theory of Socialism and Capitalism, pp. 150n–151n.

^[16] Brennan, “Hoppe’s Argumentation Ethics Argument Refuted in Under 60 Seconds”.

^[17] Brennan denies that this is true, granting it only for the sake of argument. However, Brennan never argues why Argumentation Ethics fails to establish this, so we do not take this denial into account.

^[18] Hoppe, “Hayek on Government and Social Evolution,” pp. 403–432.