 Weatherson’s theory still requires an appeal to a concept of naturalness. Without such an appeal, then if \(F\) and \(G\) are intrinsic properties that atoms could have, nothing in his theory rules out the property being simple, lonely and \(F\) or being \(G\) from being intrinsic. There are a few ways for the appeal to go at this point, see Weatherson (2001) and Lewis (2001) for a few suggestions. The following moves, taken directly from Langton and Lewis, will probably work if any will. Say that the basic intrinsic properties are those non-disjunctive properties such that their membership in \(SI\) is consistent with the above four principles. Two objects are duplicates if they do not differ with respect to basic intrinsic properties. A property is intrinsic iff it never differs between duplicates.