Leonid Zhmud The Origin of the History of Science in Classical Antiquity

History of Astronomy, as in the History of Geometry, discoveries and
theories were arranged chronologically, in accordance with the principle of
pro¯tos heurete¯s. Almost all our fragments and testimonies bear traces of this
formula, so typical of Eudemus.
45
The absence of this terminology in Cle-
ment’s testimony on Thales (fr. 143) may be the result of mere chance or, as in
the account of Callippus’ theory (fr. 149), may be explained by the context. At
any rate, it is known that Eudemus counted Thales and Callippus among the
pro¯toi heuretai. Thus, in Diogenes Laertius (I, 23 = fr. 144) we read:
Thales seems by some accounts to have been the first to study astronomy, the first
to predict eclipses of the sun and to fix the solstices, so Eudemus in his
History of
Astronomy. It was this which gained for him admiration of Xenophanes and He-
rodotus and the notice of Heraclitus and Democritus. (transl. by R. D. Hicks)
Not surprisingly, Eudemus considered Thales the founder not only of Greek ge-
ometry, but of astronomy as well (prõto~ @strolog4sai). Given that the
Catalogue assigned the invention of geometry to the Egyptians and that of
arithmetic to the Phoenicians, the
History of Astronomy was also likely to men-
tion the oriental discoverers of this science. Assuming that Eudemus’ opinion
did not sharply diverge from the earlier (and later) tradition, these precursors of
Greek astronomy must have been the Babylonians.
46
In confirmation of Thales’ achievements in astronomy, Eudemus cites as
many as four witnesses, two of whom, Xenophanes and Herodotus, are even
said to ‘have admired’ his discoveries. References to these authors may already
have been contained in Eudemus’ sources, e.g. in Hippias. Herodotus, the only
witness available to us, does not, however, show any particular admiration, con-
fining himself to a short note on Thales’ prediction of a solar eclipse (I, 74).
Whether the other three authors wrote only about the eclipse or mentioned that
Thales studied solstices as well remains unknown; Democritus could well have
touched upon the latter topic.
47
As for the eclipse prediction, Clement’s testi-
mony seems to indicate that Herodotus was one of Eudemus’ main sources:
Eudemus observes in his
Astronomical Histories that Thales predicted the eclipse
of the sun which took place at the time when the Medes and the Lydians were
joined in battle against each other. The king of the Medes was Cyaxares, the
45
prõto~ (fr. 144), e0re prõto~, ëpexeñron (fr. 145), prøtou eûrhkóto~,
prøtou~ (fr. 146), prõto~ (fr. 147), prõto~ (fr. 148).
46
See Hdt. II, 109; [Pl.]
Epin. 986e 9f.; Arist. Cael. 292a 7f. It should be noted, how-
ever, that in all three cases the Babylonians are mentioned along with the ubiquitous
Egyptians; cf. below, 8.3.
47
Democritus mentioned Thales’ parents and his Phoenician origin (68B 115a). Lebe-
dev, A. Aristarchus of Samos on Thales’ theory of eclipses,
Apeiron 23 (1990) 80f.,
attributes to Democritus the
explanation of solar eclipses that Aristarchus ascribed
to Thales; cf. below, 240 n. 49.

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Chapter 7: The history of astronomy
240
father of Astyages, and Alyattes, the son of Croesus, was the king of the Lydians.
Herodotus in the first book (of his
History) agrees with Eudemus (fr. 143).
Provided that Herodotus’ text was not assigned to Eudemus as a result of con-
tamination, the latter appears to have copied the historian’s text almost entirely.
Such unusual attention to historical detail apparently results from the absence
of more detailed evidence of Thales’ prediction (only briefly mentioned in Xe-
nophanes and Heraclitus) and probably from chronological considerations. It is
clear, at any rate, that Eudemus, facing serious problems while gathering evi-
dence on Thales’ astronomy, turned to sources he normally had no need of. Yet
the work