Beloved, we ought to listen very carefully to things for the understanding of which we are little children ... holding to this sound rule that we rejoice as if from food when we have been able to understand something according to the faith with which we have been imbued, and that, with regard to what we have not been able to understand, we set aside doubt and defer understanding; that is, that if there is something we don’t know, we never doubt that it is good and true. As for me, brothers and sisters, who have undertaken to speak to you, consider who I am and what I have undertaken. I’m a man who has undertaken to speak of the divine, a man of flesh to speak of spiritual things, a mortal man to speak of things eternal. I, too, beloved, have to flee from vain presumption if I want to live soundly in the house of God that is the Church of God, “the pillar and bulwark of truth” (1 Tim 3:15). I set before you what little I’ve been able to grasp. Where the door is open, I am fed with you; where it’s closed, I knock with you. (In Ioannem, Tr. 18, 1; PL 35, 1536)