 will generate existential commitment to a denotation for any well-formed abstract term @xΦx. This is because, in light of (ii), the self-identity @xΦx = @xΦx will also be logically true. And @xΦx = @xΦx is true only if ∃!@xΦx. This consideration holds for any defining predicate Φ. This invites the objection, raised both by Tennant (1987: 236) and by Boolos (1987: 184) that in certain conspicuous cases there is no a priori justification for commitment to the existence of denotations for these terms, in the case of particularly problematic concepts Φ (such as self-identity). This was the earliest form of the ‘Bad Company  objection’.[19] 