Augustine and Origen each give us "two birds with one stone"

Assorted retorts from yahoo boards and elsewhere: Gary Bates' Egyptian Matches Bungle the Carbon Rise · Creation vs. Evolution: Egyptian Chronology Calibrated · Augustine and Origen each give us "two birds with one stone" · Carbon 14 and Egyptian Chronology, a Reply to Gary Bates

A) They show that the Church Fathers (even those not believing in six literal days) were Young Earth Creationists.
B) They confirm that the Egyptians conflated their chronologies.

Origen, Contra Celsum, Book I
https://www.newadvent.org/fathers/04161.htm

Chapter 19

After these statements, Celsus, from a secret desire to cast discredit upon the Mosaic account of the creation, which teaches that the world is not yet ten thousand years old, but very much under that, while concealing his wish, intimates his agreement with those who hold that the world is uncreated. For, maintaining that there have been, from all eternity, many conflagrations and many deluges, and that the flood which lately took place in the time of Deucalion is comparatively modern, he clearly demonstrates to those who are able to understand him, that, in his opinion, the world was uncreated. But let this assailant of the Christian faith tell us by what arguments he was compelled to accept the statement that there have been many conflagrations and many cataclysms, and that the flood which occurred in the time of Deucalion, and the conflagration in that of Phæthon, were more recent than any others. And if he should put forward the dialogues of Plato (as evidence) on these subjects, we shall say to him that it is allowable for us also to believe that there resided in the pure and pious soul of Moses, who ascended above all created things, and united himself to the Creator of the universe, and who made known divine things with far greater clearness than Plato, or those other wise men (who lived) among the Greeks and Romans, a spirit which was divine. And if he demands of us our reasons for such a belief, let him first give grounds for his own unsupported assertions, and then we shall show that this view of ours is the correct one.

Chapter 20

And yet, against his will, Celsus is entangled into testifying that the world is comparatively modern, and not yet ten thousand years old, when he says that the Greeks consider those things as ancient, because, owing to the deluges and conflagrations, they have not beheld or received any memorials of older events. But let Celsus have, as his authorities for the myth regarding the conflagrations and inundations, those persons who, in his opinion, are the most learned of the Egyptians, traces of whose wisdom are to be found in the worship of irrational animals, and in arguments which prove that such a worship of God is in conformity with reason, and of a secret and mysterious character. The Egyptians, then, when they boastfully give their own account of the divinity of animals, are to be considered wise; but if any Jew, who has signified his adherence to the law and the lawgiver, refer everything to the Creator of the universe, and the only God, he is, in the opinion of Celsus and those like him, deemed inferior to him who degrades the Divinity not only to the level of rational and mortal animals, but even to that of irrational also!— a view which goes far beyond the mythical doctrine of transmigration, according to which the soul falls down from the summit of heaven, and enters into the body of brute beasts, both tame and savage! And if the Egyptians related fables of this kind, they are believed to convey a philosophical meaning by their enigmas and mysteries; but if Moses compose and leave behind him histories and laws for an entire nation, they are to be considered as empty fables, the language of which admits of no allegorical meaning!

Augustine, City of God, Book XII
https://www.newadvent.org/fathers/120112.htm

Chapter 10.— Of the Falseness of the History Which Allots Many Thousand Years to the World's Past.
Let us, then, omit the conjectures of men who know not what they say, when they speak of the nature and origin of the human race. For some hold the same opinion regarding men that they hold regarding the world itself, that they have always been. Thus Apuleius says when he is describing our race, Individually they are mortal, but collectively, and as a race, they are immortal. And when they are asked, how, if the human race has always been, they vindicate the truth of their history, which narrates who were the inventors, and what they invented, and who first instituted the liberal studies and the other arts, and who first inhabited this or that region, and this or that island? They reply, that most, if not all lands, were so desolated at intervals by fire and flood, that men were greatly reduced in numbers, and from these, again, the population was restored to its former numbers, and that thus there was at intervals a new beginning made, and though those things which had been interrupted and checked by the severe devastations were only renewed, yet they seemed to be originated then; but that man could not exist at all save as produced by man. But they say what they think, not what they know.

They are deceived, too, by those highly mendacious documents which profess to give the history of many thousand years, though, reckoning by the sacred writings, we find that not 6000 years have yet passed. And, not to spend many words in exposing the baselessness of these documents, in which so many thousands of years are accounted for, nor in proving that their authorities are totally inadequate, let me cite only that letter which Alexander the Great wrote to his mother Olympias, giving her the narrative he had from an Egyptian priest, which he had extracted from their sacred archives, and which gave an account of kingdoms mentioned also by the Greek historians. In this letter of Alexander's a term of upwards of 5000 years is assigned to the kingdom of Assyria; while in the Greek history only 1300 years are reckoned from the reign of Bel himself, whom both Greek and Egyptian agree in counting the first king of Assyria. Then to the empire of the Persians and Macedonians this Egyptian assigned more than 8000 years, counting to the time of Alexander, to whom he was speaking; while among the Greeks, 485 years are assigned to the Macedonians down to the death of Alexander, and to the Persians 233 years, reckoning to the termination of his conquests. Thus these give a much smaller number of years than the Egyptians; and indeed, though multiplied three times, the Greek chronology would still be shorter. For the Egyptians are said to have formerly reckoned only four months to their year; so that one year, according to the fuller and truer computation now in use among them as well as among ourselves, would comprehend three of their old years. But not even thus, as I said, does the Greek history correspond with the Egyptian in its chronology. And therefore the former must receive the greater credit, because it does not exceed the true account of the duration of the world as it is given by our documents, which are truly sacred. Further, if this letter of Alexander, which has become so famous, differs widely in this matter of chronology from the probable credible account, how much less can we believe these documents which, though full of fabulous and fictitious antiquities, they would fain oppose to the authority of our well-known and divine books, which predicted that the whole world would believe them, and which the whole world accordingly has believed; which proved, too, that it had truly narrated past events by its prediction of future events, which have so exactly come to pass!

Credits are due to Jonathan Sarfati for giving a short quote from each passage, and if he lacked the reference for St. Augustine, it was supplied by Lita Sanders earlier on.