 If one is willing to help oneself to some notion like ‘the degree of dissimilarity between \(x\) as it is at world \(w\) and \(y\) as it is at world \(w'\)’, one could use similar strategies to analyse naturalness for properties. However, this notion of “transworld resemblance” seems to cry out for further explanation. It is also worth noting that this kind of analysis looks inhospitable to the idea that the description of the world in terms of perfectly natural properties is in any sense “complete” (see §4.4.1 below): indeed, it would be rather surprising for multiple properties to be exactly tied for first place on any similarity-based measure of naturalness.