Finally, while essentialism holds certain properties as necessary for being a specific individual, related “sufficiency” theses might hold certain properties to be sufficient for being a particular individual. If, for example, we take Obama’s actual qualitative role to be a sufficient condition for an object to be identical to Obama, we thereby rule out possibilities according to which some other individual occupies Obama’s qualitative role. (Sufficiency theses of this sort can be hammered into essentialist theses by holding individuals like Obama to have essential properties like occupying the qualitative role of the President in 2014 if the world is qualitatively as it actually is.) Theses of this kind play a notable role in certain essentialist arguments—e.g., in certain arguments for origin essentialism—but it remains unclear how such principles might be used to offer a non-question-begging argument against haecceitism. (For discussion of sufficiency principles, see McKay (1986) and Robertson (1998).)