Argumentation ethics is a libertarian political theory developed in 1988 by Hans-Hermann Hoppe, a Professor Emeritus with the University of Nevada, Las Vegas College of Business and Ludwig von Mises Institute Senior Fellow. Argumentation ethics aims to prove that arguing for any ethical position other than libertarian anarchism and the non-aggression principle is logically incoherent. Responses have mainly come from Hoppe's colleagues at the Mises Institute, among whom the argument's reception has been mixed.
Hoppe states that because honest argumentation aimed at resolving a conflict over scarce resources must presuppose various norms including non-violence to be meaningful, than it follows that propositions propounded during such argumentation cannot contradict these norms, from which, he claims, the non aggression principle can be logically derived. So Hoppe claims that to deny the non aggression principle during such argumentation is a performative contradiction between one's actions and one's words. For example, to argue that violence should be used to resolve conflicts is an obvious performative contradiction if one is to engage in a meaningful argument to resolve such a conflict.
Hoppe states that his theory is an a priori, value-free praxeological argument for deontological libertarian ethics. Argumentation ethics asserts the non-aggression principle is a presupposition of every argument and so cannot be logically denied during an argument. Argumentation ethics draws on ideas from Jürgen Habermas's and Karl-Otto Apel's discourse ethics, from Misesian praxeology and from the political philosophy of Murray Rothbard.
As stated by Hans Hermann Hoppe himself (see e.g.https://www.youtube.com/watch?v=b8UE3QAV8JM watch from min 2' 30"), his theory was found independently by nl:Frank van Dun in Gent, Belgium in 1970 in his ph.D. work titled "Het Fundamenteel Rechtsbeginsel" ( http://www.rothbard.be/bestanden/boeken/FRB.pdf ).
Hoppe first notes that when two parties are in conflict with one another they can, eventually, choose to resolve the conflict by one of two means. Engaging in violence, or engaging in honest argumentation. In the event that they choose argumentation, Hoppe asserts that the parties must have implicitly rejected violence as a way to resolve their conflict. He therefore concludes that non-violence is one of the underlying norms (Grundnorm) of meaningful argumentation that is accepted by both participants.
Hoppe states that since because both parties act to propound propositions in the course of such argumentation, and because argumentation must presuppose certain norms (that he specifies, non-violence among them), then the content of the propositions cannot negate the presupposed propositions of argumentation. To do so is a performative contradiction between one's actions and one's words.
Argumentation ethics aims to show the non-aggression principle (in a certain formulation) follows from the presuppositions of argumentation, and so it cannot be denied.
Other than dismissing propositions calling for violence as means to resolve conflict, Hoppe also argues that only universal norms are consistent with such meaningful argumentation, as, he claims, arbitrary categorical distinctions have no intersubjective justification, which also must be a presupposition of such argumentation. Hoppe then also argues that since argumentation requires the active use of one's body, all universal norms for resolving conflicts over the human body aside from self-ownership are inconsistent with argumentation, as they would not allow one to independently move. Hoppe then argues that since the resolution of conflicts over external resources must also be objectively justifiable, only the physical establishment of an objective link by original appropriation (i.e., homesteading) is a norm compatible with such a requirement. From these Hoppe concludes that only the non-aggression principle of self-ownership and Lockean homesteading can be justified in an argument without contradiction.
Bearing reference to the legal doctrine of estoppel, Stephan Kinsella's "Dialogical Estoppel" theory extends argumentation ethics by considering an argument between a victim and aggressor. Kinsella argues that an aggressor cannot consistently object to being proportionally punished for his act of aggression, by the victim or by the victim's representatives, because by committing aggression he commits himself to the proposition that the use of force is legitimate, and therefore, his withholding consent based on a normative right not to be physically harmed contradicts his aggressive legitimation of force, i.e. he is "estopped" from withholding consent.
Various responses to Hoppe's argument came from Mises Institute scholars. Some of them accepted his argument, among them attorney Kinsella and economists Walter Block and Murray Rothbard, who called it "a dazzling breakthrough for political philosophy in general and for libertarianism in particular," adding "he has managed to transcend the famous is/ought, fact/value dichotomy that has plagued philosophy since the days of the Scholastics..."
Mises Institute economists Bob Murphy and Gene Callahan rejected Hoppe's argument. The late Austrian Economist David Osterfeld, an adjunct scholar at the Mises Institute, also rejected Hoppe's argument in an essay to which Hoppe subsequently responded. Walter Block has since defended the argument and Marian Eabrasu rebuts a wide range of criticisms.
Ludwig Von Mises Institute Senior Fellow and Auburn University philosopher Roderick Long reconstructed the argument in deductively valid form, specifying four premises on whose truth the argument's soundness depends. Long goes on to argue that each premise is either uncertain, doubtful, or clearly false. He summarizes his views by stating:
I don’t think there's any reason to reject out of hand the kind of argument that Hoppe tries to give; on the contrary, the idea that there might be some deep connection between libertarian rights and the requirements of rational discourse is one I find attractive and eminently plausible. [...] But I am not convinced that the specific argument Hoppe gives us is successful.
A political theorist has concluded in a doctoral dissertation on the political philosophy of several Austrian economists that Hoppe has not provided any non-circular reasons why we "have to regard moral values as something that must be regarded as being established through (consensual) argument instead of 'mere' subjective preferences for situations turning out in certain ways". In other words, the theory relies on "on the existence [of] certain intuitions, the acceptance of which cannot itself be the result of 'value-free' reasoning."