5.7.12   For after it was clear that he was ignorant of those arts in which I thought he excelled, I began to despair of his opening and solving the difficulties which perplexed me (of which indeed however ignorant, he might have held the truths of piety, had he not been a Manichee). For their books are fraught with prolix fables, of the heaven, and stars, sun, and moon, and I now no longer thought him able satisfactorily to decide what I much desired, whether, on comparison of these things with the calculations I had elsewhere read, the account given in the books of Manichaeus were preferable, or at least as good. Which when I proposed to he considered and discussed, he, so far modestly, shrunk from the burthen. For he knew that he knew not these things, and was not ashamed to confess it. For he was not one of those talking persons, many of whom I had endured, who undertook to teach me these things, and said nothing. But this man had a heart, though not right towards Thee, yet neither altogether treacherous to himself. For he was not altogether ignorant of his own ignorance, nor would he rashly be entangled in a dispute, whence he could neither retreat nor extricate himself fairly. Even for this I liked him the better. For fairer is the modesty of a candid mind, than the knowledge of those things which I desired; and such I found him, in all the more difficult and subtile questions.