Thomas Cahill says that Augustine, fascinated with Plato’s concept of man seeking Truth, considers Paul’s writings, and is brought to the point of wondering whether humans are capable of seeking and acquiring truth.
Cahill imagines that Augustine must have read Romans 8:29ff (concerning God’s role in salvation) and concluded something like
[I]f we mud-spattered human beings are ever to ascend to Truth, we can do it only because God, a force ineffably greater than our war-torn selves, has predestined us and calls us upward. We will never make it under our own steam.
Having made this connection, Augustine falls apart.
Thomas Cahill, How the Irish Saved Civilization 56 (1995).