Advanced draft toward the published version On Ex(s)istere: Revisiting the “to Be”–“to Exist” Debate Richard Colledge Published in: Proceedings of the American Catholic Philosophical Association Vol 82, 2008 ABSTRACT This paper looks to revive and advance dialogue surrounding John Nijenhuis’ case against ‘existence language’ as a rendering of Aquinas’ esse. Nijenhuis presented both a semantic/grammatical case for abandoning this practice as well as a more systematic argument based on his reading of Thomist metaphysics. On one hand, I affirm the important distinction between being and existence and lend qualified support to his interpretation of the quantitiative/qualitative correlation between esse and essentia in Aquinas’ texts. On the other hand, I take issue with Nijenhuis’ relegation of exist(ence) to a second-rate ontological principle, and to this end undertake a brief historical and etymological survey, noting its emergence in Greek thought (u9pa/ rxein, u3parcij), its translation into medieval Latin (ex(s)istere, ex(s)istentia) and thus something of the pedigree of this terminology in modern usage. I conclude with some brief remarks on the task of exegeting Aquinas vis-à-vis the revivification of contemporary metaphysical ontology in general.