Man and Sin by Piet Schoonenberg (1964) 2.3 FA
[Speculative reason was obviously superior to practical reason.
Augustine started as a Manichean because it was the philosophy of those who considered themselves better the common folk.
Then, Augustine experienced a change of heart.
In doing so, he ultimately placed the speculations of the Manicheans in the same inferior position as Manicheans put common folk.
The interscope of Manichean speculation became the intersection of Augustine’s heart.]