Łukasz Dominiak, “Must Right-Libertarians Embrace Easements by Necessity?“, 34 Diametros 16 (2019), 60: 34–51.
The present paper investigates the question of whether right-libertarians must accept easements by necessity. Since easements by necessity limit the property rights of the owner of the servient tenement, they apparently conflict with the libertarian homestead principle, according to which the person who first mixes his labor with the unowned land acquires absolute ownership thereof. As we demonstrate in the paper, however, the homestead principle understood in such an absolutist way generates contradictions within the set of rights distributed on its basis. In order to avoid such contradictions, easements by necessity must be incorporated into the libertarian theory of property rights and the homestead principle must be truncated accordingly.
Everyone seems to ignore what seems obvious to me, and was put out there by a commenter on your original article criticizing the Blockian proviso: if the donut owner is in possession of the donut hole and is able to exclude others from using it without permission, it is owned.
Would it make sense for the donut owner to somehow claim and defend the donut but disclaim the hole? Can someone have standing to dispute the donut owner, not on use of the donut, but about access to the hole? I don’t think so. By assumption of the thought experiment, no one can use the hole without trespassing on the donut, which in effect makes the hole part of what is owned, whether or not it is used or the owner particularly cares.
So the contradiction is in the assumptions of the thought experiment, not in property rights.
A more interesting case is where the donut owner creates the donut by buying some land, and someone owns the donut hole already. Perhaps they already have an easement on whatever means they used previously to access it? Does that mean that the donut owner must tolerate whatever the hole owner does, and can never exclude them for any reason? No, because an easement is a restriction on an owner, not full ownership. The hole owner has a right to access, but not the full rights of ownership of the easement.
Except they don’t ignore this–I have explicitly made this argument.
I should have said, the author of the linked article and Walter Block, seem to ignore this. I suppose we can imagine a bad legal arrangement where the ability to deny access does not count as embordering, but we can also imagine communism. Being able to imagine it, or even being able to impose it on one’s neighbors, does not prevent it from being nonsense.