Is There An Actual Difference in God Between Essence and Person (Aquinas' Answer)

"I answer that, The truth of this question is quite clear if we consider the divine simplicity. For it was shown above (Question 3, Article 3) that the divine simplicity requires that in God essence is the same as 'suppositum,' which in intellectual substances is nothing else than person. But a difficulty seems to arise from the fact that while the divine persons are multiplied, the essence nevertheless retains its unity. And because, as Boethius says (De Trin. i), 'relation multiplies the Trinity of persons,' some have thought that in God essence and person differ, forasmuch as they held the relations to be 'adjacent'; considering only in the relations the idea of 'reference to another,' and not the relations as realities. But as it was shown above (Question 28, Article 2) in creatures relations are accidental, whereas in God they are the divine essence itself. Thence it follows that in God essence is not really distinct from person; and yet that the persons are really distinguished from each other. For person, as above stated (29, 4), signifies relation as subsisting in the divine nature. But relation as referred to the essence does not differ therefrom really, but only in our way of thinking; while as referred to an opposite relation, it has a real distinction by virtue of that opposition. Thus there are one essence and three persons."

Summa Theologica (Prima Pars, Quaestio 39, Article 1)

The Summa Theologica of St. Thomas Aquinas

Second and Revised Edition, 1920

Literally translated by Fathers of the English Dominican Province

Online Edition Copyright © 2008 by Kevin Knight