Since Lewis analyzes de re representation—i.e., the way in which entities represent de re possibilities—in terms of qualitative resemblance, counterpart relations never divide qualitatively indiscernible entities (i.e., for any qualitatively indiscernible entities \(x\) and \(y\) in a given context, \(x\) is a counterpart of \(z\) if and only if \(y\) is a counterpart of \(z)\). This commitment has serious consequences for the modal realist treatment of haecceitism. In particular, it guarantees that qualitatively indiscernible possible worlds do not differ in terms of what de re possibilities they represent. Lewis therefore endorses the following thesis about the connection between qualitative properties and what de re possibilities a world represents: