  However, the specter of possibilism is not so easily exorcised. For  non-actual worlds are not the only, or even the most compelling,  examples of mere possibilia that seem to emerge out of basic  possible world semantics. For instance, it is quite reasonable to  think that evolution could have taken a very different course (or, if you like, that God could have made very different creative choices)  and that there could have been individuals — call them  Exotics — that are biologically very different from  all actually existing individuals; so different, in fact, that no  actually existing thing could possibly have been an Exotic. According to basic possible world semantics, the sentence ‘There could  have been Exotics’ or, more formally, 