1. To make a case that possible worlds exist, in what ways can they be accounted for.
2. Is the cosmos ‘large enough’ to guarantee or make probable the existence of all possible worlds: does the infrastructure exist, does the hotel have enough rooms.
3. If possible worlds exist, why might it follow (or not follow) that all possible worlds exist.
4. If some possible worlds exist concretely but not all, is it because a set of criteria beyond the logical constrain the set of possible worlds that are existent, or it it arbitrary — some worlds happen to exist and others don’t — or is it a mixture of specific criteria and arbitrariness.
5. What are the minimum conditions for the concrete existence of a world, logical, metaphysical, mathematical, or physical, or otherwise. (That is, what sort of infrastructure does there need to be, what fundamental bits and pieces, sat there in the inventory of a world, in order that the world has a shot at substantial existence).
6. If by some definition a set of possible worlds exist, and if it is fair to say that actuality is all there is that exists concretely, why shouldn’t we just consider them part of ‘actuality’ rather than separate realms.
7. If there are phenomena that some people consider to be part of the world, and others consider to be other worlds — possible worlds — is there a substantive difference between the two positions or only a semantic one? Does the question of possible worlds collapse under this pressure.