Ownership of physical property is natural because physical property is inherently rivalrous and excludable — if you take my hammer, I can't use it, and thus I need to keep my hammer in my shed if I want to have access to it when I need it. Ownership makes natural sense there. It's essential to security.

Ideas are not the same way. Any number of people can think an idea, and in fact an idea becomes just as much a part of everyone who thinks it as the first person who thought it, and you literally can't take an idea back once you have shared it. Ideas are not just easy to copy, they aren't even entities that need copying. The mind is constantly taking in and assimilating ideas and creating its own.

I'm not actually against copyright. I think there is a sound moral basis for it, in that otherwise an increasing number of people wouldn't be able to enjoy the fruits of their labor. I just don't think there is a moral justification for the tortured concept of eternal copyright. Eventually, any successful idea will become so diffused throughout society that it's just an utter farce to pretend it is not part of the commons.

If nothing else, infinitely decreasing the number of ideas that may be legally had is so harmful to society that it outweighs any good that could possibly come from it. In other words, even if we say "Sure, let's pretend treating ideas as property is a natural fit," the Lockean Proviso warns us against allowing them to remain property forever.

> Ownership of physical property is natural because physical property is inherently rivalrous and excludable

While that's one philosophical justification for property, we've had property long before anyone coined the phrases "rivalrous" or "excludable" and it has been justified for reasons that have nothing to do with those economic concepts: http://en.wikipedia.org/wiki/Labor_theory_of_property. Going back further, see Psalm 128:2 ("For thou shalt eat the labour of thine hands: happy shalt thou be, and it shall be well with thee.")

Ideas are just inherently unlike physical property on a very fundamental level. If my neighbor lends me his hammer, I can give it back. If my neighbor lends me an idea, it never left him, but I still can't ever rid myself of it.

No matter how much I care about content creators being compensated fairly — and I do, both for philosophical and selfish reasons — it is a farce to pretend an idea that exists in everyone's heads and originated in none of them is the exclusive property of one person. It is simply unnatural in a way that physical property isn't.

I created Harry Potter, not J.K. Rowlings? My labor in reading the novels is equal to her labor in writing them?

I think that argument falls flat particularly with copyright because there is no copyright liability in the face of independent creation. Copyright doesn't prevent anyone from owning their original ideas, even if other people independently think of the same idea.

So with that hammer you build products that you might sell and I might want to buy with my money that I got from selling my idea. But if you 'take' my idea I will have to get a new hammer just the same. There are infinitely many hammers as there are infinitely many ideas, but getting new one takes nontrivial amount of effort for both cases. The fact that one is tangible is in my opinion an arbitrary property for the purpose of this discussion.

Copyrights and patents were created specifically for the purpose of recouping development costs that are otherwise non-recoverable by the more obvious laws of microeconomics.

You're not just comparing apples and oranges. You're comparing actual apples to poems that rhyme the word orange.

The reason others are owed rights is that copyright, as with patents, is a contract between the state and the creator/inventor. Part of the deal is that creators get copyright protection in return for the eventual entry of the work in to the public domain - they pay off the demos with that promise.

State doesn't owe creators of works protection naturally. If creators want to not have a limited right to exclusive use they should be allowed to give that up and then the state should exclude itself from any actions against people who copy that work.

To recapitulate: if you don't want to 'buy' copyright protection with eventual movement of your work in to the public domain then you can instead have that work freely copyable - without tort - based on the ability of anyone who sees/uses it. Without ready movement of works in to the public domain the public are being ripped off, the contract is broken and the public then should consider those works copyable without the possibility of a claim of tort.

They are. All someone has to do is include in it a statement to the effect of 'I waive my copyright interest in this work and hereby donate it to the public domain.' There is no bar on voluntary placement of work into the public domain; it just doesn't happen that often because when publishers write checks to authors they're purchasing the right to exploit the work commercially. Authors could grant publishers limited licenses to do so and then stipulate that the work would fall into the public domain after a certain date, but that would result in lowered payments from publishers, plus it creates an incentive for the publisher to under-market the work or even withhold it from sale, and then publish it once it enters the public domain without paying anything in royalties.

There are some publishers that make good money of just republishing historical works, even without exclusivity. Some people want a good-quality facsimile of an old book. Dover paperbacks springs to mind.

Perpetuities ultimately end up with contending claims. Adjudicating those is tremendously expensive.