City of God - Book 15, Section 9
Augustine addresses the apparent longevity of people in the Book of Genesis. He writes that it is reasonable to suppose that early men were mightier than modern men, and that both historical records and archeological evidence support this idea. He also writes that there are historical records from not that long ago referring to people who lived up to 200 years.
Of the long life and greater stature of the antediluvians.
Wherefore no one who considerately weighs facts will doubt that Cain might have built a city, and that a large one, when it is observed how prolonged were the lives of men, unless perhaps some sceptic take exception to this very length of years which our authors ascribe to the antediluvians and deny that this is credible. And so, too, they do not believe that the size of men's bodies was larger then than now, though the most esteemed of their own poets, Virgil, asserts the same, when he speaks of that huge stone which had been fixed as a landmark, and which a strong man of those ancient times snatched up as he fought, and ran, and hurled, and cast it,—
"Scarce twelve strong men of later mould
That weight could on their necks uphold;"
thus declaring his opinion that the earth then produced mightier men. And if in the more recent times, how much more in the ages before the world-renowned deluge? But the large size of the primitive human body is often proved to the incredulous by the exposure of sepulchres, either through the wear of time or the violence of torrents or some accident, and in which bones of incredible size have been found or have rolled out. […] But, as I said, the bones which are from time to time discovered prove the size of the bodies of the ancients, and will do so to future ages, for they are slow to decay. But the length of an antediluvian's life cannot now be proved by any such monumental evidence. But we are not on this account to withhold our faith from the sacred history, whose statements of past fact we are the more inexcusable in discrediting, as we see the accuracy of its prediction of what was future. And even that same Pliny tells us that there is still a nation in which men live 200 years. If, then, in places unknown to us, men are believed to have a length of days which is quite beyond our own experience, why should we not believe the same of times distant from our own?
Many anti-Creationist arguments go something like this: “That can’t have happened because that’s not the way things happen today.” This is an appeal to uniformitarian presumptions: the idea that things have always been the same as they are today, so we cannot appeal to any special circumstances that may have occurred in the past. For example, if the Grand Canyon is slowly being eroded away by the Colorado River, then the slow action of erosion must have formed the Grand Canyon. The possibility that the Grand Canyon may have been formed during a cataclysmic event is automatically discounted as a possibility.
Augustine addressed the uniformitarian fallacy around 1600 years ago in his conclusion to this section:
[Are we not to] believe that in other times there has been anything but what is now?