I thought I detected a libertarian strain in Robin's arguements on this and on other issues, but perhaps I am wrong about this. If he is using libertarian arguements, then such arguements rely on a unitary self, as follows:Gosh! That was easy!
Libertarianism is based on a person's self-ownership, with liberty to do whatever he wants with his self, as long as he allows others the same liberty.
But with multiple subselves within the same person, when one subself takes an action it will often restrict the liberty of another subself, thus making a nonsense of the libertarian project.
My poor little sub-selves! how they have been suffering all these years! Living under the totalitarian rule of umm... other... umm... sub... selves...