Nozick builds a beautiful mental model in the first subsection of Chapter 10 of ASU (pp. 297-306). This simple model has the following parts (p. 299):
- Universal imagining rights. “Imagine a possible world in which to live; this world need not contain everyone else now alive, and it may contain beings who have never actually lived. Every rational creature in this world you have imagined will have the same rights of imagining a possible world for himself to live in (in which all other rational inhabitants have the same imagining rights, and so on) as you have.” That is, you are allowed to imagine your own possible utopia or association and you are allowed to populate your imaginary society with as many or little “rational creatures” as you like, but everyone else in your world is also allowed to imagine their own utopian associations.
- Universal emigration rights. “The other inhabitants of the world you have imagined may choose to stay in the world which has been created for them (they have been created for) or they may choose to leave it and inhabit a world of their own imagining.” In two words, open borders!
- Iteration. There is no arbitrary stopping point. This process of imagining new utopian associations and entrance into and exit from these imaginary societies will continue indefinitely until someone imagines a world that people want to voluntarily join and remain in.



