When men seek to know God, and bend their minds according to the capacity of human weakness to the understanding of the Trinity; learning, as they must, by experience, the wearisome difficulties of the task, whether from the sight itself of the mind striving to gaze upon light unapproachable, or, indeed, from the manifold and various modes of speech employed in the sacred writings (wherein, as it seems to me, the mind is nothing else but roughly exercised, in order that it may find sweetness when glorified by the grace of Christ);— such men, I say, when they have dispelled every ambiguity, and arrived at something certain, ought of all others most easily to make allowance for those who err in the investigation of so deep a secret. But there are two things most hard to bear with, in the case of those who are in error: hasty assumption before the truth is made plain; and, when it has been made plain, defense of the falsehood thus hastily assumed. From which two faults, inimical as they are to the finding out of the truth, and to the handling of the divine and sacred books, should God, as I pray and hope, defend and protect me with the shield of His good will, and with the grace of His mercy, I will not be slow to search out the substance of God, whether through His Scripture or through the creature.
Source: Translated by Arthur West Haddan. From Nicene and Post-Nicene Fathers, First Series, Vol. 3. Edited by Philip Schaff. (Buffalo, NY: Christian Literature Publishing Co., 1887.) Revised and edited for New Advent by Kevin Knight.
Picture Source: Thanks to https://upload.wikimedia.org/wikipedia/commons/e/ea/Saint_Augustine_by_Philippe_de_Champaigne.jpg