I recently came upon an email exchange posted at Economic Policy Journal between past Lions of Liberty Podcast guest Walter Block and an emailer, who wrote to Block regarding whether Murray Rothbard should be regarded as a "thick" libertarian. The emailer suggests that since Rothbard wrote about extra-libertarian topics that he should be considered a "thick" libertarian, in contrast to "thin" libertarians who believe that libertarianism should concern itself solely with the non-aggression principle.I believe this exchange offers some important insight, and I reprint it below with permission from Dr. Block (Block's comments are in bold):

I received this important challenge to libertarianism:A position opposed to initiatory aggression was not enough for Rothbard when he wrote that David Friedman's anarchism was not good enough because he did not "hate" the State. This is an extra-libertarian preference.A position opposed to initiatory aggression was not enough for Rothbard when he supported diversity in human relations. He went so far as to call egalitarianism "evil" as against human nature. The same can be said for his stance on hermeneutics.A position opposed to initiatory aggression was not enough for Rothbard when he split society into the ruling class and the subject class. I don't have to tell you that he drew heavily on Leftist historians for this material and this sort of class theory is exactly something you would find among left thick libertarians todayThis is not to say Rothbard was good or bad for any of this. I just recognize that his intellectual project was not just the NAP, and that all of his commitments were of a greater worldview -- a Rothbardian worldview. Here are my responsese (<<) But Murray was far more than merely a libertarian. He was also an Austrian economist, a philosopher, an ethicist, a historian, a strategist for libertarianism (this is different than being a libertarian; the former asks how liberty can best most efficaciously be promoted, the latter is limited to deductions from the non aggression principle) and much more.  If Murray said any of these things QUA libertarian, I would agree with you. Murray would then be a thickster libertarian. But I don’t agree that Murray spoke as a libertarian on any of the points you make. Let me consider each of these points:A position opposed to initiatory aggression was not enough for Rothbard when he wrote that David Friedman's anarchism was not good enough because he did not "hate" the State. This is an extra-libertarian preference. <<Yes, this is “an extra-libertarian preference.” But note, Murray didn’t say that David was not a libertarian. Only that he didn’t like that viewpoint, in effect. So, Murray is not speaking here as a libertarian. He would have been had he said that since David didn’t hate the state, David wasn’t a libertarian. But Murray didn’t say this.A position opposed to initiatory aggression was not enough for Rothbard when he supported diversity in human relations. He went so far as to call egalitarianism "evil" as against human nature. << Hey, Murray was also “Mr. First Nighter.” That is, Murray gave movie reviews. Did he do so as a libertarian? Of course not. He did so as a movie critic. Libertarians are allowed to take stands on non libertarian issues. They just do not do so qua libertarian; rather, they should not do so from that perspective. Suppose the following scenario: we have laissez faire capitalism, full free enterprise, and somehow everyone ends up with precisely the same amount of wealth and income. This is not a logical contradiction. What would Murray’s view on that scenario have been? Of course I cannot speak for him, but it seems to me he would have said something of the order of, “well, that’s the way the cookie crumbles. I do not at all oppose voluntary egalitarianism, or egalitarianism that arises from economic freedom. I think it extremely unlikely, given what I know of the heterogeneity of the human race, but this would not violate the NAP. I only oppose coercive egalitarianism, since it violates the NAP.” Here, the Murray of my imagination would be speaking as a libertarian, but this would hardly be thick.The same can be said for his stance on hermeneutics. << Here, Murray spoke as an Austrian economist, not as a libertarian.A position opposed to initiatory aggression was not enough for Rothbard when he split society into the ruling class and the subject class. I don't have to tell you that he drew heavily on Leftist historians for this material and this sort of class theory is exactly something you would find among left thick libertarians today.  <<Yes, thick libertarians buy into this too, and why not? It is an accurate portrayal of economic history. But what is the distinction between rulers and ruled. It is certainly not the Marxist one between employers and employees. Rather, it is based on NAP violations. The rulers do this, and the victims suffer from it. So this is also thin libertarianism. Best regards,  Walter

As a side note, it's quite true that there has existed a class structure both throughout world history and in our modern world today. Many modern commentators such as Thomas Piketty attempt to blame this on free markets. In reality we can trace much of modern day disparity not on the ability of people to freely associate, but rather their inability to do so, largely thanks to the crony capitalist / fascist system in place throughout most of the world today. Many large corporations use government as a tool by which they violate the rights of individuals via patents, licensing, subsidies and other favorable regulations. To point this out is perfectly in line with libertarianism, both thick and thin.I'll share more thoughts on the thick vs. thin debate below, but first, a follow-up exchange between Block and the emailer, starting with the response to Block:

Thank you, this is helpful.For what it's worth, I gather that Rothbard is a borderline case. His guiding star was unequivocally the NAP, but he had episodes of thickness.Much of the issue depends on our definition of thickness. If Rothbard's class theory is thin, then so is much of self-described thick libertarianism (e.g., on the FDA/contraception issue). And if Rothbard's Austrian economics is to be separated from his libertarianism, then so should Roderick Long's feminism be separated from his libertarianism. Likewise, if the Friedman episode is not evidence of Rothbard's thickness because his tangential disagreement with Friedman did not cause him to question Friedman's libertarianism, then the same can be said for all thick-v-thin debates, wherein no thick libertarian (to my knowledge) expunges thin libertarians from libertarianism.We are faced, I think, with a continuum: how interlaced must non-libertarian commitments be with libertarianism before thinness turns into thickness?Egalitarianism is illustrative. I am sure you're right that Rothbard would say noncoercive egalitarianism is no problem. But Rothbard did not make that distinction in the essay. His point was that egalitarianism was impossible, anti-human, and evil. At the time, therefore, he was defending the ideal of inequality, and he did so in the context of combating radical leftism, including communism. Like Hoppe defends conservatism, this is a thick position because his stance on inequality and on libertarianism are intimately connected. Yet if you had noted the possibility of noncoercive egalitarianism (like you might challenge his position on copyright or on licensure), I am sure Rothbard would have changed his mind in accordance with a more consistent NAP, and would likely have added a clarifying paragraph, separating his libertarianism from his non-egalitarianism. This would be a thin position.If you grant that thin-v-thick is a continuum, then it is not really our place to decide whether Rothbard was thin or thick on these issues. It is his place. But since he is not around to settle the issue for us, the best we can do is to describe him as we do on IP: though he favored copyright, he did so before Kinsella was around to change his mind. Thus: though Rothbard had episodes of thickness, he would likely distinguish them all with a thin commitment to the NAP, had this debate been around to clarify his position.

And back to Walter Block:

Here’s my substantive reply:You may well be right. If we comb through everything Murray ever wrote or spoke about, publicly or privately, we might come up with some few cases of thickness in his libertarianism. Who knows? He wrote so much, he might conceivably have erred in this regard a few times; hey, no one is perfect. However, the burden of proof rests with those, such as you, who claim he was a thick libertarian, and so far you have not laid a single glove on him.Lookit, Roderick Long’s support of feminism, anti bossism, anti racism, etc., is problematic, thickish, because he claimed these were part of libertarianism, and they are not. Certainly, feminism, for example, stands for principles incompatible with pure or correct libertarianism. In very sharp contrast, Murray Rothbard’s support for Austrianism has nothing whatever to do with libertarianism. The former lies in the positive realm the latter within the normative, and these are very different.  See this as a clarification of that point:Block, Walter E. and Peter Cappelli. 2013. “Debate over the normative positive distinction in economics.”  Economics, Management, and Financial Markets 8(1), pp. 11-19;  http://addletonacademicpublishers.com/abstracts/economics-management-and-financial-markets/volume-8-1-2013/debate-over-the-normative-positive-distinction-in-economics.htmlOf course Murray didn’t discuss the wild-eyed idea that full free enterprise could lead to perfect egalitarianism. The entire idea is silly, given human beings as we know them. Lookit, his point there made the not so heroic assumption of human heterogeneity. Is he to be allowed no implicit assumptions upon pain of being characterized as a thick libertarian.I appreciate your point about continuums. I make that same point here:Block, Walter and William Barnett II. 2008. “Continuums”  Journal Etica e Politica / Ethics & Politics, Vol. 1, pp. 151-166, June;  http://www2.units.it/~etica/ ;  http://www2.units.it/~etica/2008_1/BLOCKBARNETT.pdfLet me concede, arguendo, that Murray wrote in a way that could be interpreted as thick libertarian, oh, 3 times in his entire professional life; remember, this is arguendo, since not one case in point has so far been shown.  Given our agreed upon point of continuums, we could not fairly characterize Murray as a thickster. In contrast, Roderick Long is a very thick libertarian. He positively revels in this fallacy.I agree with you that Hoppe, in his defense of conservatism, takes on a thick position. I made that point here:Block, Walter E. 2010. “Libertarianism is unique; it belongs neither to the right nor the left: a critique of the views of Long, Holcombe, and Baden on the left, Hoppe, Feser and Paul on the right.”  Journal of Libertarian Studies; Vol. 22: 127–70;  http://mises.org/journals/jls/22_1/22_1_8.pdf; http://141.164.133.3/exchange/walterblock/Inbox/JLS%20article.EML/1_multipart_xF8FF_2_block%20libertarianism%20is%20unique%20one.pdf/C58EA28C-18C0-4a97-9AF2-036E93DDAFB3/block%20libertarianism%20is%20unique%20one.pdf?attach=1 http://mises.org/journals/scholar/block15.pdf;  http://www.mises.org/journals/scholar/block15.pdfHowever, he does so very rarely. He is not at all in the same camp as Long who does this a lot, given our agreement on continuums.

I've written before on the thick vs. thin debate, and while if forced at gunpoint I would lean "thin", I believe the overall debate to be a distraction from what libertarians should be focusing on: the philosophy of liberty. The non-aggression principle is certainly a key tenet of that philosophy, but it is not enough, all alone without context or philosophical underpinnings, to fully encapsulate libertarianism. It's my view that libertarianism should concern itself with the fundamental concept of individual rights - not merely their violation, but their conception as well. The philosophy behind why it is wrong to initiate violence - aka "aggress" - against other individuals is just as if not more important that the acceptance of non-aggression itself.Libertarianism should not concern itself with issues that do not relate directly to individual rights. This does not mean that libertarian individuals shouldn't value other social issues, or examine how social hierarchies shape the world we live in.I personally have no problem if two people of the same gender want to get married. But one could certainly hold a personal belief that a man and another man shouldn't get married and still be a libertarian, so long as that person did not advocate the use of violence against those individuals to prevent them from doing so. There is nothing wrong with the Jeffrey Tuckers of the world wishing for a society where nobody discriminates, everyone is for gay marriage, and loves drinking bourbon. It is only if and when he would declare these desires requirements for libertarianism that I, as well as self-identified "thin" libertarians such as Walter Block, would take issue.Check out the full Mondays with Murray archive!Receive access to ALL of our EXCLUSIVE bonus audio content – including “Conspiracy Corner”, “Degenerate Gamblers” and the “League of Liberty Podcast” by joining the Lions of Liberty Pride and supporting us on Patreon!