Christ would establish a literal 1,000-year kingdom prior to the general resurrection, but later rejected the belief, viewing it as carnal. During the medieval period, the Catholic Church built its system of eschatology on Augustinian amillennalism, where Christ rules the earth spiritually through his triumphant church. During the Reformation, theologians such as John Calvin accepted amillennialism. Augustine taught that the eternal fate of the soul is determined at death, and that purgatorial fires of the intermediate state purify only those who died in communion with the Church. His teaching provided fuel for later theology. Mariology Although Augustine did not develop an independent Mariology, his statements on Mary surpass in number and depth those of other early writers. Even before the Council of Ephesus, he defended the Ever-Virgin Mary as the Mother of God, believing her to be "full of grace" (following earlier Latin writers such as Jerome) on account of her sexual integrity and innocence. Likewise, he affirmed that the Virgin Mary "conceived as virgin, gave birth as virgin and stayed virgin forever". Natural knowledge and biblical interpretation Augustine took the view that, if a literal interpretation contradicts science and humans' God-given reason, the biblical text should be interpreted metaphorically. While each passage of Scripture has a literal sense, this "literal sense" does not always mean the Scriptures are mere history; at times they are rather an extended metaphor. Original sin Augustine taught that the sin of Adam and Eve was either an act of foolishness (insipientia) followed by pride and disobedience to God or that pride came first. The first couple disobeyed God, who had told them not to eat of the Tree of the knowledge of good and evil (Gen 2:17). The tree was a symbol of the order of creation. Self-centeredness made Adam and Eve eat of it, thus failing to acknowledge and respect the world as it was created by God, with its hierarchy of beings and values. They would not have fallen into pride and lack of wisdom if Satan had not sown into their senses "the root of evil" (radix Mali). Their nature was wounded by concupiscence or libido, which affected human intelligence and will, as well as affections and desires, including sexual desire. In terms of metaphysics, concupiscence is not a state of being but a bad quality, the privation of good or a wound. Augustine's understanding of the consequences of original sin