My point isn't about IP, it's about how easy it is to twist this way of reasoning with story and analogy in any direction you want by choosing a different analogy.

If your original post was anti-IP, I'd just twist it into pro-IP case. Or if you used aynrandist story about "self-ownership" + analogy to capitalism, I'd use a different analogy that makes it strongly oppose capitalism. Or whatever.

As long as there's "let's pick arbitrary analogy" step anywhere in your reasoning system, it's all infinitely twistable.

The part about Coase theorem was about how your analogy choice was highly unusual. Not that using a more obvious one would entirely avoid the problem.

It quite probably has, and would.

Well, Hermione's sorting is another example of Hat taking person's preferences into account.

Is there any good counter-example?

Me wanting desperately to be a Hufflepuff because it gives me access to a whole lot of Hufflepuffs to be my loyal minions might not be quite so persuasive.

I'd expect people to develop serious plans of taking over the world at some age older than 11, but feel free to write fanfic to the contrary.

But if you believed strongly in value of loyalty, that might be enough. Hermione, Neville, and Peter Pettigrew all seem to have been sorted based on their value system more than on their actual traits - otherwise their sorting makes little sense.

Slytherins by definition lack necessary bravery to keep getting into all fights that maintaining a position within feudal system requires.

As long as acquiring power requires personally charging into an enemy army, Gryffindors will hold most of it. Fellow Gryffindors will be easily impressed by someone who does so without a second thought. Slytherins won't last long. To someone who actually values their life and comfort like all Slytherins do, this is very expensive kind of signaling.

I'm not arguing for or against copyrights on this basis; I was just a convenient example of Parfitian reasoning that I could conveniently twist.

I can think of a lot of nitpicking applicable to both scenarios. Like this:

Copyleft is a very limited tool, especially against patents, while without IP you can produce many works with other forms of funding - like work contracts. It's nearly impossible to produce a work that isn't based on other's freely available works (regardless if this kind of derivation counts as legally "derivative work" or not), while sticking IP on trivial things just because you can is commonplace. In sufficiently strong IP system pretty much nothing would ever be created, because everything would violate far too many other people's IP, so it is indeed self-defeating.

I'm sure you can find some other minor differences, and we could go on indefinitely, at least until we figured out that maybe this isn't the best way to reason.

On another level, I have no idea why you used Omaga as analogous to IP instead of far more obvious analogy to plain old legally enforceable contracts.

The only defense for IP that makes even tiniest bit of economic sense is that transaction costs would prevent consumers negotiating with producers. By straightforward Coase theorem reasoning, for any work that would be profitably produced in IP-based system, at least as good or better outcome could be achieved without IP system if transaction and negotiation costs were zero (plus a few other totally unrealistic assumptions, but none worse than assuming omniscient Omega).

Feudalism feels more like Gryffindor to me. It was more about personal authority than about cunning. Not to mention he was the one with the sword.

But what would be the point? Has the Sorting Hat ever placed anyone in a House they very strongly didn't want to be placed?

It assigned Harry to Gryffindor not Slytherin because Harry was strongly against the idea of joining Slytherin.

I'd guess with strict system like that, most people get pre-conceptions about which house they belong to long before sorting, so Hat's job is usually very easy.

Here's the original form:

So, to wrap it up, what does Parfit's Hitchhiker have to do with intellectual property? Well:

• Omega represents the people who are deciding whether to produce difficult, satisfying intellectual works, conditional on whether we will respect certain exclusivity rights that have historically been promised them.
• The decision to rescue us is the decision to produce those intellectual works.
• The decision to pay the $5 represents the decision to continue to respect that exclusivity once it is produced "even though" they're "not scarce anymore", and we could choose otherwise.

But it could just as easily be:

• Omega represents the people who are making their work freely available, conditional on whether we will keep derivative works likewise freely available
• The decision to rescue us is the decision to produce those intellectual works
• The decision to pay the $5 represents the decision to make your work freely available, "even though" you can as well stick a copyright on it, and make some money

Can it get more opposite? Full rejection of IP, with form identical to supportive argument.

You can rationalize anything this way.

World used to be filled with revolutionary movements, and very few managed to grow past Dunbar's number or so before falling apart by everyone trying to out-politic everyone else.

Only very few that were extraordinarily loyal like Bolsheviks won. The primary difference between Bolsheviks and everyone else was their strong belief in strict loyalty to the party, whose decisions were to be absolutely binding upon all members.

Even after they started killing each other, very few defected the Party to join some other group.

Compare it with far more typical Slytherining in Kyrgystan where people keep joining, defecting, and plotting everyone against everyone else.

It was made by founders of Hogwarts. Possibly Dark Lord or Dumbledore could cast a spell like that, but few 11 year olds or their parents.