E. E. Constance Jones was one of the first women to study philosophy at the University of Cambridge. This paper focuses on her claim from her first major work, Elements of Logic as a Science of Propositions, that each thing has a unique existence. Jones’s claim follows from claims about tropes and haecceities; but, I suggest, it’s not claims about tropes and haecceities that lead her to accept it. Rather, I suggest, it’s claims about what she calls the denomination of (...) names and the quantitiveness of things that lead her to accept it. Her claim that each thing has a unique existence thus fits within her more general views in Elements of Logic. (shrink)