Thus there are two sets of apparently contradictory texts in Thomas Aquinas. There are those texts where he speaks of essence as somehow possessing an actuality of its own, as that which receives esse , as that which limits esse . And Carlo is impelled not only to unify these two strands of texts, but to set out to reduce essence to existence as much as possible. We certainly agree with Father Phelan that essences are modes of being, that they are intrinsic modifications of esse . It is non-ens because it is other than ipsum esse which it receives from another.
Essence flows from esse .
Esse gives rise to essence. Essence is the intrinsic modification of the dynamism of actual exercise of the act of being. This doctrine of the non-being of essence and the ultimate reducibility of essence to esse is, I think, a logical consequence of the interpretation of essence as a mode of being. And submerged in his preoccupation of the relationship between essence and existence is a hint of what is to come. Just as in the case of essence, St. Thomas has two strands of texts about matter.