xi.) I demonstrated the existence of God; it is evident, I repeat, from that proof, that the existence of God, like his essence, is an eternal truth.

Further (in Prop.xix.

of my "Principles of the Cartesian Philosophy"), I have proved the eternity of God, in another manner, which I need not here repeat.
PROP.XX.

The existence of God and his essence are one and the same.
Proof .-- God (by the last Prop.) and all his attributes are eternal, that is (by Def.

viii.) each of his attributes expresses existence.