I have a different take from Bryan Caplan's on the debate between Nick Gillespie and Matt Welch, on the one hand, and David Gordon, on the other. My take is informed by the further discussion that Bryan doesn't mention: Welch's response to Gordon and Gordon's rejoinder. Rather than leave you in suspense, I'll tell you my bottom line: they aren't disagreeing at all on what Gordon thought they were disagreeing on. Gordon probably still has remaining disagreements, but they are not the main one he highlights in his initial critique.
Start with the following statement from Gillespie and Welch that David Gordon quotes:
While there are competing definitions of what 'libertarian' means, the simplest understanding attaches to people who believe that government is less efficient than the private sector, that people should be left alone as much as possible to lead their own lives, and that tolerance is the most important social value.
The key thing to know is what Gillespie and Welch mean by the word "tolerance." I don't know if they define it--unfortunately, I haven't read their book. But the dictionary that comes with my Mac defines "tolerance" as "the ability or willingness to tolerate something, in particular the existence of opinions or behavior that one does not necessarily agree with."
So now we must look up "tolerate." The first two parts are the ones that apply:
1. allow the existence, occurrence, or practice of (something that one does not necessarily like or agree with) without interference : a regime unwilling to tolerate dissent.
2. accept or endure (someone or something unpleasant or disliked) with forbearance : how was it that she could tolerate such noise?
Note the idea of allowing, accepting, even enduring. Nowhere in the definition of "tolerate" is there the idea of embracing or liking a particular group, practice, race, type of music, etc. "Tolerance," in short, seems to mean the belief in the idea of "live and let live." Notice that Bryan used exactly that term, "live and let live," to talk about tolerance. But "live and let live" is simply a popular way--one of the best, in my opinion--not only to define tolerance but also to characterize libertarianism. The idea is that I might not like the fact that you wear tattoos on your neck, say, but I don't use coercion to stop you. Or I might not like the fact that you, with an annual of income of $50,000, have decided to spend $10,000 of it annually on an expensive car, but I don't use coercion to stop you.
So with this definition of tolerance, Gillespie and Welch on the one hand and David Gordon on the other are not disagreeing at all.
But somehow Gordon has the idea that by "tolerance," Gillespie and Welch mean not only that one must accept, allow, and endure, but also that one must embrace other cultures, types of music, races, etc. I had wondered whether they meant that too. In his response, though, Welch makes clear that he doesn't mean that. Welch writes:
Our book's main point in discussing rock music was not to bully people into favoriting [sic] our record collections (Gillespie's, by his own admission, is terrible), but to celebrate the art form's potency as a force for personal and even national liberation, a fact that contradicts many of the official and unofficial condemnations of the stuff as setting back the cause of human liberty.
Welch argues that rock music has undercut totalitarian regimes. Whether he's right or wrong--I think he's right--one can embrace that argument without embracing rock music.
I would have expected David Gordon, one of the most careful readers I have ever known, to say, although he would probably said it better, "Oh, now I get it; I can still regard rock music as raucous noise but that doesn't, in Welch's view, undercut my libertarian credentials." Instead, here's what he actually said:
I am glad to learn that Welch does not think that you have to like rock music to be a libertarian. I stand corrected: apparently what you have to like is that other people like rock music. You must also deplore those who fear that this style of music will have bad consequences.
But there's no "have to" or "must." Again, Welch is simply pointing out that rock music has had good effects in creating liberty in totalitarian regimes. You don't have to like the fact that it has.
Having said all this, I am not saying that Gillespie/Welch and Gordon don't have real disagreements. But disagreement over tolerance is not one of them.