Saint Augustine. Even his name sounds big. Like Goliath. I feel like I am taking on a giant here, because as far as Christian thinking goes, he certainly looms large, but he was wrong, so I shall call him Gus.
He veers sharply from reality in the first sentence of his first paragraph, when he states that, "God ... derived all men from one individual ... (God) created man..." and "the one (man) was created out of nothing, ..." Gus got right to the point with his fallacies. He was wrong in two ways, first, it is impossible to create something from nothing. I will not offer an in depth defense of this statement here for lack of room and time, but suffice it to say that there has never been an observed example of something coming from nothing in the physical realm. Second, modern genetic research suggests that Homo Sapiens did in fact experience a population bottleneck some 70,000 years ago when the Toba Volcano exploded, and though there is much debate about how few Homo Sapiens remained after that cataclysm, the accepted range of surviving humans is between ten and two thousand.
But Gus would say that God exists outside of the material world, and that I am missing the point by arguing such small matters. He would be right of course. The bigger issue here is the existence of God. If I were to attempt to take on Gus point for point, I would have to write a book larger than "The City of God".
But disproving the existence of God, Gus would say, is impossible! Maybe, but I don't have to do that. Rather, the burden of proof for a mythology as baseless as Christianity lies not on me, but on those who profess the myth as truth. I have evidence to support what I believe. Gus, sadly, produced not a shred of it. I no more have to believe what he says than I have to believe someone who says the aliens are coming on the next comet to take them away.
Gus spent quite a bit of time trying to defend and explain the concept of free will in the presence of his omniscient god. The trouble is that a god who knows everything by definition knows what is about to happen. This presents a problem to any free spirit who thinks they can choose to do what they want when they want. If our free-spirited fellow decides to hop on one foot, blow a smoke ring, and then juggle sea bass, Gus's god would just say, I knew you were going to do that! It is quite demoralizing to try to throw a surprise birthday party for the god of the bible. Furthermore, it is very hard to salvage free will as a concept when somewhere in the universe a being exists who has known for all eternity that today you have an appointment to juggle sea bass at exactly 3:46 pm. Some claimed that the act of choosing was at best experiential, and not really effectual. It was, in the editorial matter of the text, "a link in the causal chain or, perhaps, a curious side effect. William James later called this the "epiphenomenon". I like to think that Alexander the Great, as much a student of his master Aristotle as Plato was of Socrates, would have, sliced this Gordian Knot in two.
The question of how Man can have free will in the presence of an all-knowing God can be a baffling conundrum until someone happens by and comments, "There is no God".
Therefore the City of God, deprived of it's foundation, crumbles and falls.
To use Gus's own argument, how can one see a God that isn't there? It is like listening to silence.