 So, by adopting Modal Monism, Chalmers places primary possibility within the same modal realm as secondary possibility. This guarantees that primary possibility is no less “real” or “genuine” than secondary possibility (indeed, as Chalmers puts it, “these worlds are all first-class metaphysical possibilities” [2002: 165]) Thus, the kind of possibility that is entailed by primary, positive, ideal conceivability, is a metaphysical one.