St. Gregory of Nyssa’s Advice to Theologians
In speaking of God, when there is question of His essence, then is the time to keep silence. When however, it is a question of His operation, a knowledge of which can come down even to us, that is the time to speak of His omnipotence by telling of His works and explaining His deeds, and to use words to this extent. In matters which go beyond this, however, the creature must not exceed the bounds of his nature, but must be content to know itself. For, indeed, in my view, if the creature never comes to know itself, never understands the essence of the soul or the nature of the body, the cause of being…, if the creature does not know itself, how can it ever explain things which are beyond it? Of such things it is the time to keep silence; here silence is surely better. There is, however, a time to speak of those things by which we can in our lives make progress in virtue.
*Taken from Commentary on Ecclesiastes.