8. And who ordered this Mani to write about these things, knowledge of which is not necessary to piety? For thou hast said to man, "Behold, godliness is wisdom"--and of this he might have been ignorant, however perfectly he may have known these other things. Yet, since he did not know even these other things, and most impudently dared to teach them, it is clear that he had no knowledge of piety. For, even when we have a knowledge of this worldly lore, it is folly to make a profession of it, when piety comes from confession to thee. From piety, therefore, Mani had gone astray, and all his show of learning only enabled the truly learned to perceive, from his ignorance of what they knew, how little he was to be trusted to make plain these more really difficult matters. For he did not aim to be lightly esteemed, but went around trying to persuade men that the Holy Spirit, the Comforter and Enricher of thy faithful ones, was personally resident in him with full authority. And, therefore, when he was detected in manifest errors about the sky, the stars, the movements of the sun and moon, even though these things do not relate to religious doctrine, the impious presumption of the man became clearly evident; for he not only taught things about which he was ignorant but also perverted them, and this with pride so foolish and mad that he sought to claim that his own utterances were as if they had been those of a divine person.
9. When I hear of a Christian brother, ignorant of these things, or in error concerning them, I can tolerate his uninformed opinion; and I do not see that any lack of knowledge as to the form or nature of this material creation can do him much harm, as long as he does not hold a belief in anything which is unworthy of thee, O Lord, the Creator of all. But if he thinks that his secular knowledge pertains to the essence of the doctrine of piety, or ventures to assert dogmatic opinions in matters in which he is ignorant--there lies the injury. And yet even a weakness such as this, in the infancy of our faith, is tolerated by our Mother Charity until the new man can grow up "unto a perfect man," and not be "carried away with every wind of doctrine."
But Mani had presumed to be at once the teacher, author, guide, and leader of all whom he could persuade to believe this, so that all who followed him believed that they were following not an ordinary man but thy Holy Spirit. And who would not judge that such great madness, when it once stood convicted of false teaching, should then be abhorred and utterly rejected? But I had not yet clearly decided whether the alternation of day and night, and of longer and shorter days and nights, and the eclipses of sun and moon, and whatever else I read about in other books could be explained consistently with his theories. If they could have been so explained, there would still have remained a doubt in my mind whether the theories were right or wrong. Yet I was prepared, on the strength of his reputed godliness, to rest my faith on his authority.