5.14.25   Hereupon I earnestly bent my mind, to see if in any way I could by any certain proof convict the Manichees of falsehood. Could I once have conceived a spiritual substance, all their strongholds had been beaten down, and cast utterly out of my mind; but I could not. Notwithstanding, concerning the frame of this world, and the whole of nature, which the senses of the flesh can reach to, as I more and more considered and compared things, I judged the tenets of most of the philosophers to have been much more probable. So then after the manner of the Academics (as they are supposed) doubting of every thing, and wavering between all, I settled so far, that the Manichees were to be abandoned; judging that, even while doubting, I might not continue in that sect, to which I already preferred some of the philosophers; to which philosophers notwithstanding, for that they were without the saving Name of Christ, I utterly refused to commit the cure of my sick soul. I determined therefore so long to be a Catechumen in the Catholic Church, to which I had been commended by my parents, till something certain should dawn upon me, whither I might steer my course.

.