 Next, some authors (e.g. Mares 1997) favor Nolan’s SIC principle (introduced in  section 2.5).  This implies that any possible world is closer to @ than any impossible world is to @. A system of spheres for impossible worlds centered on @ will just extend the intuitive possible worlds spheres described above, by adding further, larger spheres where worlds outside (logical, or more generally unrestricted) possibility stand. But how are these latter to be internally ordered?