For over 700 years scholastic theologians of varying degrees of allegiance to the text(s) of Thomas Aquinas have discoursed on the mystery of Christ's being (esse): Did Christ have one or two acts of existence? Yet despite this frequent and recurring quaestio, nevertheless only a handful of scholastic commentators pause to note that this is not simply a debate between rival scholastic ‘schools’ in regard to a theological mystery, but that in fact there is an inconsistency within the Angelic doctor's own texts. And while in more recent scholarship this discrepancy has not only been noticed but explicated in various ways, nevertheless it is the contention of this paper that a satisfactory exposition of the meaning of esse secundarium has not yet been achieved. Consequently, I propose in this paper that esse secundarium is the created, substantial, but absolutely supernatural participation of the human nature of Jesus in the uncreated communication of the divine esse of the Word and provide a robust textual defense of this interpretation.