 In the face of this failure, we might still hope that a yet more sophisticated broadly logical analysis might succeed. An argument due to Marshall and Parsons, however, shows that, given standard views about what is possible, and given the absence of special assumptions about the abundance and structure of properties, no such analysis can be given. Marshall and Parsons consider the intrinsic property of being an electron and the extrinsic property of being either an accompanied electron or a lonely positron. They then show that, given certain common views about properties and possibility, these properties have the same pattern of instantiation through logical, mereological and set-theoretic space. Since formulas containing only broadly logical expressions cannot distinguish between properties having the same such pattern, it then follows that no broadly logical analysis of intrinsically is possible. (This argument was developed jointly by Marshall and Parsons, and then presented briefly in Parsons 2001 and in more depth in Marshall 2009.) 