Charles Taylor, in Sources of the Self, contrasts Augustine and Plato by pointing out that Plato does not actually hold to “innate ideas” in the way that Augustine does. For Plato, even memory is really a means to point one outside of himself to the prenatal vision of the forms. Augustine, on the contrary, believes that God planted a certain amount of moral knowledge into man in creation, thus making man the image of God. To look to one’s self, for Augustine, is not necessarily to look away from God.
For Plato, things are always different. Man has to get outside of himself, to look outward to the divine order which rules over him. Man has a certain natural capacity, but that is only a capacity to grasp something else. Man is always ruled by the laws above him.