The third volume of the Blackfriars Summa Theologiae, translated by Herbert McCabe, is entitled (I have always supposed by him) Knowing and Naming God. These words make a concise brief for the philosopher of religion. Of its two movements, knowing God seems at first glance the more demanding and critical, yet it is evident that for Aquinas and the Patristic tradition which preceded him, naming God was of equal difficulty and weight. In fact the two cannot be separated for to name one must, in some sense know which, for the early theologians, formed an almost insurmountable obstacle to our speaking of God.
Augustine is continuously occupied with how we can know God, and with how we can name Him. It is the problem with which he opens the Confessions, for if we do not know what or whom we address then how can we call upon our Lord? To call upon we need a name, and a name involves definition and definition risks idolatrously presuming to know the divine essence.
How shall I call upon my God, my God and my Lord, when by the very act of calling upon him I would be calling him into myself?
The primary Biblical text for the naming of God for Patristic and medieval readers alike was Exodus 3. 1-14, the story of Moses at the burning bush. Moses, herding his father-in-law’s sheep, is addressed by God and in the negotiations which follow Moses asks the Deity for a name,
And God said to Moses ‘I AM WHO I AM’ —you must say to the sons