Note 74 — Chapter XIX · APPLICATION OF CHRONOLOGY TO GRECIAN LEGEND.
Reading edition
The distinction which Mr. Clinton draws between an upward and a downward chronology is one that I am unable to comprehend. His doctrine is, that upward chronology is trustworthy and practicable up to the first recorded Olympiad; downward chronology is trustworthy and practicable from Phorôneus down to the Ionic migration: what is uncertain is, the length of the intermediate line which joins the Ionic migration to the first recorded Olympiad,—the downward and the upward terminus. (See Fasti Hellenici, vol. i. Introduct. p. ix. second edit. and p. 123, ch. vi.)
All chronology must begin by reckoning upwards: when by this process we have arrived at a certain determined era in earlier time, we may from that date reckon downwards, if we please. We must be able to reckon upwards from the present time to the Christian era, before we can employ that event as a fixed point for chronological determinations generally. But if Eratosthenês could perform correctly the upward reckoning from his own time to the fall of Troy, so he could also perform the upward reckoning up to the nearer point of the Ionic migration. It is true that Eratosthenês gives all his statements of time from an older point to a newer (so far at least as we can judge from Clemens Alex. Strom. 1, p. 336); he says “From the capture of Troy to the return of the Herakleids is 80 years; from thence to the Ionic migration, 60 years; then, farther on, to the guardianship of Lykurgus, 159 years; then to the first year of the first Olympiad, 108 years; from which Olympiad to the invasion of Xerxês, 297 years; from whence to the beginning of the Peloponnesian war, 48 years,” etc. But here is no difference between upward reckoning as high as the first Olympiad, and then downward reckoning for the intervals of time above it. Eratosthenês first found or made some upward reckoning to the Trojan capture, either from his own time or from some time at a known distance from his own: he then assumes the capture of Troy as an era, and gives statements of intervals going downwards to the Peloponnesian war: amongst other statements, he assigns clearly that interval which Mr. Clinton pronounces to be undiscoverable, viz. the space of time between the Ionic emigration and the first Olympiad, interposing one epoch between them. I reject the computation of Eratosthenês, or any other computation, to determine the supposed date of the Trojan war; but, if I admitted it, I could have no hesitation in admitting also the space which he defines between the Ionic migration and the first Olympiad. Eusebius (Præp. Ev. x. 9, p. 485) reckons upwards from the birth of Christ, making various halts, but never breaking off, to the initial phenomena of Grecian antiquity,—the deluge of Deukalion and the conflagration of Phaëtôn.