Let me now lay bare in the sight of God the twenty-ninth year of my age. There had just come to Carthage a bishop of the Manicheans named Faustus, a great snare of the devil; and many were entangled by him through the charm of his eloquence. Now, even though I found this eloquence admirable, I was beginning to distinguish the charm of words from the truth of things, which I was eager to learn. Nor did I consider the dish as much as I did the kind of food that their famous Faustus served up to me in it. His fame had gone before him as a man very skilled in honorable learning and preeminently skilled in the liberal arts. And as I had already read and stored up in memory many of the injunctions of the philosophers, I began to compare some of their doctrines with the tedious fables of the Manicheans; and it struck me that the probability was on the side of the philosophers, whose power reached far enough to enable them to form a fair judgment of the world, even though they had not discovered the sovereign Lord of it all.⁠a For you are great, Lord, and you have regard for the lowly, but you know the proud from afar. You draw near to none but the contrite in heart, and cannot be found by the proud, even if in their inquisitive skill they may number the stars and the sands, and map out the constellations, and trace the courses of the planets.
For it is by the mind and the intelligence which you gave them that they investigate these things. They have discovered much; and have foretold, many years in advance, the day, the hour, and the extent of the eclipses of those luminaries, the sun and the moon. Their calculations did not fail, and it happened as they predicted. And they wrote down the rules they had discovered, so that to this day they may be read and from them may be calculated in what year and month and day and hour of the day, and at what quarter of its light, either the moon or the sun will be eclipsed, and it will happen just as predicted. And men who are ignorant in these matters marvel and are amazed; and those who understand them exult and are exalted. Both, by an impious pride, withdraw from you and forsake your light. They foretell an eclipse of the sun before it happens, but they do not see their own eclipse which is even now occurring. For they do not ask, as religious men should, what is the source of the intelligence by which they investigate these matters. Moreover, when they discover that you made them, they do not give themselves up to you so that you might preserve what you have made. Nor do they offer, as sacrifice to you, what they have made of themselves. For they do not slaughter their own pride—as they do the sacrificial fowls—nor their own curiosities by which, like the fishes of the sea, they wander through the unknown paths of the deep. Nor do they curb their own extravagances as they do those of "the beasts of the field," so that you, Lord, "a consuming fire," may burn up their mortal cares and renew them to immortality.
They do not know the way which is your word, by which you created all the things that are and also the men who measure them, and the senses by which they perceive what they measure, and the intelligence by which they discern the patterns of measure. So they do not know that your wisdom is not a matter of measure. But the Only Begotten has been "made to us wisdom, and righteousness, and sanctification" and has been numbered among us and paid tribute to Caesar. And they do not know this "Way" by which they could descend from themselves to him in order to ascend through him to him. They did not know this "Way," and so they fancied themselves exalted to the stars and the shining heavens. And see, they fell to the earth, and "their foolish heart was darkened." They saw many true things about the creature but they do not seek with true piety for the Truth, the Architect of Creation, and so they do not find him. Or, if they do find him, and know that he is God, they do not glorify him as God; neither are they thankful but become futile in their thinking, and say that they themselves are wise, and attribute to themselves what is yours. At the same time, with the most perverse blindness, they wish to attribute to you their own quality—so that they load their lies on you who are the Truth, "changing the glory of the incorruptible God for an image of corruptible man, and birds, and four-footed beasts, and creeping things." "They exchanged your truth for a lie, and worshiped and served the creature rather than the Creator."
Yet I remembered many true sayings of the philosophers about the creation, and I saw the confirmation of their calculations in the orderly sequence of seasons and in the visible evidence of the stars. And I compared this with the doctrines of Mani, who in his voluminous folly wrote many books on these subjects. But I could not discover there any account, of either the solstices or the equinoxes, or the eclipses of the sun and moon, or anything of the sort that I had learned in the books of secular philosophy. But still I was ordered to believe, even where the ideas did not correspond with—even when they contradicted—the rational theories established by mathematics and my own eyes, but were very different.