 If we take the special case in which \(w =\) the actual world (call it “@”), we get a natural arrangement of possible worlds in a system of spheres that mirrors their degree of (dis)similarity with respect to @, according to the different kinds of possibilities and (relative) impossibilities they represent. For instance, a world which is exactly like @, except that Franz wears a white t-shirt instead of the black one he’s actually wearing while writing these lines, is, intuitively, closer to @ than a world at which the laws of physics are turned upside down. Some people have a general, intuitive depiction of such closeness relations, and set out a hierarchy of modalities accordingly: possible worlds where the laws of physics are different from ours are naturally seen as more eccentric than worlds where only biological, but not physical, laws are different; and these are more eccentric than possible worlds with minimal factual changes with respect to @, such as the white t-shirt world.