Miscellanies 5.12.82

And if we sometimes name it, calling it, though not properly, the One, or the Good, or Mind, or Being itself, or Father, or God, or Maker, or Lord, we do not speak as though uttering his name; but for lack of anything better we use fair names, so that the mind may have these to lean on and not wander about among other things. For none of them singly shows what God is, but all of them together indicate the power of the Almighty. For the things we say of anything are said either from what belongs to it or from its relation to other things, and none of these can be applied to God. Nor is he grasped by demonstrative knowledge; for that is built from what is prior and better known, and nothing exists before the Unbegotten. It remains, then, that we understand the Unknown by divine grace and by the Word alone that comes from him, as Luke too records in the Acts of the Apostles, where Paul says: “Men of Athens, I see that in every way you are very religious. For as I went about and looked at the objects of your worship, I found also an altar on which was inscribed, ‘To an unknown god.’ What therefore you worship in ignorance, this I proclaim to you.”