"For Rousseau, man's nature is essentially good, but he was corrupted by various “advances” in human civilization (especially the institution of private property). Although man's natural “innocence” has been lost, Rousseau thought that it could be replaced by a new form of moral goodness through the establishment of new political institutions. When we compare this to St. Augustine, we can see what a departure this is from the mainstream of Pauline Christianity. Augustine held that man is inescapably sinful and concludes that, as such, the City of God cannot be achieved on earth. Rousseau's major contribution to the foundation of socialist thought is in his rejection of human sinfulness and his commitment to human improvement through institutional change. With this foundational belief, he set the stage for perfectionist political doctrines that moved focus from “the next world” of Christianity by arguing that this world can be transformed into “heaven on earth.”"