Since I'm into and enjoying the study of Blessed Aquinas these days... This should help(I hope) ...... "That in Created Subsistent Intelligences there is a Difference between Existence and Essence": .....(quote from Aquinas)
Hence in Exodus iii, 14, existence is assigned as the proper name of God, He who is: because it is proper to God alone that His substance is none other than His existence.
Excellent. Shame on me for not thinking of this. God IS: "I AM". That we even exist, or can know it, is fully dependent on God existing first.
“Excellent. Shame on me for not thinking of this. God IS: “I AM”. That we even exist, or can know it, is fully dependent on God existing first.”
Almost. What Blessed Thomas is saying is just what The Fathers said. God “is” or God “defines” existence. He is not saying that God “exists”, thus, “...because it is proper to God alone that His substance is none other than His existence.”