Augustine's epochal doctrine of grace is often portrayed as a break from his earlier Platonism, but in Inner Grace, Phillip Cary argues it should be seen instead as the way Augustines Platonism developed as he read the apostle Paul. Augustines concept of grace as an inner gift that moves, turns and strengthens the will from within requires a Platonist conception of the soul's inner relation to the Good. What he adds to this conception is that grace is needed not only for the mind to see God but also for the will to turn away from lower goods and love God as its eternal Good, and even for it to choose faith in Christ, the temporal road by which the soul journeys to God. Thus over the course of Augustine's career the scope of the soul's need for grace expands outward from intellect to love and then to faith. At every stage, Augustine insists that divine grace does not compromise or coerce the human will but frees, helps and strengthens it, precisely because grace is not an external force but an inner gift of delight. But as his polemic against the Pelagians develops, increasingly more is attributed to grace and less to the power of free will.
At the end of his career this results in an explicit doctrine of predestination, according to which it is ultimately God who chooses who shall be saved. Behind predestination therefore is divine election, which Augustine understands as God choosing some rather than others for salvation. This contrasts with the Biblical doctrine of election, Cary argues, in which some are chosen for the blessing of others: e.g., Israel for the nations and Christ for the world. In this Biblical doctrine, grace and blessing are external rather than inner gifts, because they always come to us from others outside us.