I recently wrote an article, available here, on the idea of thick libertarianism. Below I outline the core of the argument.
Starting from Austro-libertarian premises, thick libertarianism is unavoidable. Austro-libertarians are committed to the non-aggression principle (NAP) and in order to identify acts of aggression in the real world, in some cases, have to make judgements which necessarily call upon moral and political considerations outside of the NAP itself. It seems that some of these considerations are going to be more in keeping with the reasons a libertarian has for endorsing the NAP than others. In Charles Johnson’s taxonomy, this is application thickness: The idea that there are moral and political reasons for interpreting certain acts as aggression rather than others that are more coherent with thin libertarian commitments.
From an Austro-libertarian perspective, aggression is a praxeological type. That is to say it’s a category of action that has certain logical structure that can be grasped a priori. We do not need to observe aggressive acts a certain number of times, and see that they all constitute the non-consensual crossing of a property boundary in order to induce that non-consensual boundary crossings all seem to be aggressive. Rather, non-consensual boundary crossings are necessarily aggressive. Therefore, without any empirical observation, we know that if a non-consensual boundary crossing occurred, the NAP was violated. There was a victim of this aggression, and there was a perpetrator, and some sort of redress is due. Praxeological reasoning can therefore be done from the armchair. If x was a non-consensual boundary crossing, x violated the NAP. Identifying x as a boundary-crossing however cannot be done from the armchair. One must look at the actual incident in question, and interpret it as such. Physical movements of human bodies in the world do not come ready-tagged as whatever praxeolgical types they are; they must be interpreted as such by real persons.
Two praxeological types which are centrally important for the sake of identifying NAP violations in the world are consent and the initiation of aggression. When consent is given to a boundary crossing, the NAP is not violated, and if A initiated aggression against B before B used force against A, then B’s boundary crossing against A is justifiable as self-defense. Therefore, when and where we identify human behaviour as constituting these praxeological types has profound moral and political implications.
In the paper, I discuss two cases. The first is a boss who takes his secretary to have consented to having sex with him whenever he wants by her signing of her employment contract. The second is a white man who takes a black man’s behaviour to be a threat, and shoots him in purported self-defense. These cases illustrate that the interpretation one takes of the action of others means one can believe oneself to be respecting the NAP, but under a different interpretation of those actions, one violated it.
The two different interpretations, moreover, might be perfectly reasonable given the agent in question’s background. Which interpretation we take as the one that bears legal consequence has enormous moral and political implications, and as such is subject to moral and political evaluation. One ought, therefore, have the best moral and political reasons for taking whatever interpretation one does. These reasons might be consistent with the reasons one has for endorsing the NAP, or they may be inconsistent. Either way, thick libertarianism is possible if we can find the reasons to guide how we interpret other people’s actions which best fit with our reasons for being libertarians. Application thickness is thus unavoidable for an Austro-libertarian.