(b) Even still, every term, class-referring or not, is indeed “ambiguous.” My point was not that “libertarianism” (as I’ve defined it) is ambiguous, but that the ambiguity is a particularly problematic one, and bears the particular implications I outlined.

(c) Again, it is not required that one consciously assent to “proportional libertarianism” to be an “exemplator” of the “set” of believers in it—only that some other belief(s) of his imply this logically. (Though, again, my point is slightly more complex—that the “libertarianism” claim must mean, when consistently rendered, the “proportional” view OR one of either of the two other views treated.)

I have to stress that this whole thing is a logical exercise. Even if nobody believes (1) now, they might go there when the doors to (2) and (3) (of the three views treated) are closed in the course of the argument. It is like C.S. Lewis’s argument that Christ must have been a “liar, lunatic, or Lord.” Nobody (nobody he is addressing) actually thinks Christ is a liar or a lunatic (the sets have no “exemplator[s]”), but that doesn’t make the exercise worthless. It forces the reader to choose one of three logically possible options implicit within their belief that Christ is a worthy moral teacher but not God. It is, in fact, because the sets are empty that the argument works. (Well, it works for the audience, given false beliefs they already hold–but that’s another story.) I’m not sure that’s what I’m doing, but in the extreme case that I were, it still wouldn’t be a pointless enterprise.

(2) I am not certain which of us is unsophistocated about this particular issue, but one of us sure is. Of course, most people would argue that government must define and enforce property rights, and, of course, there are alternative different ways to make certain choices about that original definition and the techniques of enforcement, but THE POINT IS that once those decisions are made they are not perpetually modified on a day by day and case by case basis. The same is not true of regulation or other forms of government intervention [as we are now seeing in the credit markets]. Here, perhaps this will help http://www.sfu.ca/~allen/CoaseJLE1960.pdf
I would also suggest that you read the chapters on Economic Calculation in this http://www.amazon.com/Individualism-Economic-Order-F-Hayek/dp/0226320936 and, finally, on an alternative view as to how property right definition and enforcement might occur without a government, take a look at http://www.amazon.com/Enterprise-Law-Justice-Without-State/dp/0936488301/ref=sr_1_1?ie=UTF8&s=books&qid=1223843916&sr=1-1

(b) The reason I had to explore multiple interpretations is because the libertarian “claim” is damned ambiguous. Take your own rendering: “Markets work and central direction of economic affairs…are always a disaster. Period.” You substitute this for my own rendering of libertarianism (before I “multiply interpret” it) as if mine and yours are not as good as synonyms. Again: Just what does “central direction” mean? Any old quantity of central direction? (So if the state intervenes in the market just once in 200 years, to buy a half-price hamburger for the President, the economy will undergo “disaster”?) And what is the alternative? Less central direction than we have now?—How much less, and how do we know when we’ve gotten to that amount? No central direction at all?—Is that possible? (But I direct you to the—entire—essay.)

[i.e., When you say, "a movement from a lot of government interference in the market to somewhat less interference does not make things better," you are simply rejecting one of the possible interpretations of libertarianism which I lay out—namely, the one you quote (and mistakenly think I ascribe to some actual libertarians). This is fine; read on: I offer two other possible ways to interpret libertarianism, and refute those as well. That is, you either want (a) a lot, lot, lot less gov. interference than the "less" we have now, or (b) no interference at all. Is there a third interpretation of "interference is bad for the market" I've overlooked?]

(c) Whether any actual libertarians explicitly “take” one (or any) of the three positions I attack is immaterial, because that isn’t the only way to “take” a position. My point is that the position itself can only mean—if it is to have meaning—one of the three options. (Then again, maybe it has no meaning–but I’m being generous.) No flesh-and-blood libertarian has to assent to one (or any) of the views in real life for this to be the case. The position is ambiguous and must “go” in one of these three directions if it is to not be. My essay forces libertarians to pick one of a trichotomy of positions, each leading to absurd conclusions. (There’s probably a latin name for that but I don’t know it.)

(d) I think I said all this in the essay—right?

Two things: (1) This is what is called a strawman. I know of no libertarian [at least no libertarian who is recognized by his fellow libertarians as a libertarian] who takes this position. The libertarian position is that markets work and central direction of economic affairs, including “regulation” are always a disaster. Period. (2) This issue was explored in what is technically known as “general equilibrium theory” or “welfare economics” in the 1960s under the label “the theory of the second best”. The conclusion of those studies was that a movement from a lot of government interference in the market to somewhat less interference does not make things better. An economy is like an ecology, small scale or erratic tinkering can have just as catastrophic effects as large scale tinkering.

In other words, you fail the test for knowing your subject before starting to type.