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

Meteorology Aristotle criticizes one of Hippocrates’ astronomi-
cal theories, the ancient sources are silent on his discoveries in this science.
More prominent in the history of astronomy were his two contemporaries,
Meton and Euctemon of Athens, whose
floruit is traditionally dated by the sol-
stice they observed on June 28, 432. Meton and Euctemon made systematic ob-
servations in different regions of Greece, created the first astronomical calend-
ars, the so-called parapegmata, suggested a new 19-year calendar cycle, and
determined the inequality of the four astronomical seasons. Quite famous in
their time,
173
they were the earliest of the Greek astronomers whose dated ob-
cerpt from Dercyllides (cf.
Exp., 199.3–5 and 202.8–10). Hence, Wehrli concluded
that the Eudemian origin of this passage is doubtful. Now, Theon is much more
likely to have repeated the sentence quoted previously from Dercyllides than to have
edited the quotation in his own manner and repeated it verbatim once again.
173
Meton figured in Phrynichus (
Schol. Ar. Av. 997a) and Aristophanes (Av. 992–1019);

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Chapter 7: The history of astronomy
268
servations are cited by Ptolemy.
174
Eudemus, it seems, had much to tell about
their discoveries. Unfortunately, the fragments of the
History of Astronomy
contain only a brief reference to one of them – the inequality of the four sea-
sons, mentioned in connection with Callippus’ modification of Eudoxus’ sys-
tem:
According to Eudemus, Callippus asserted that, assuming the periods between
the solstices and equinoxes to differ to the extent that Euctemon and Meton held
that they did, the three spheres in each case (i.e., for the sun and moon) are not
sufficient to save the phenomena, in view of the irregularity which is observed in
their motions (fr. 149).
According to Meton’s and Euctemon’s calculations, the seasons are 90, 90, 92
and 93 days long, starting with the summer solstice.
175
This shows, contrary to
what Eudoxus’ system has postulated,
176
that the sun’s motion along the eclip-
tic is unequal. Did Meton and Euctemon themselves realize their calculations’
significance for astronomy, not just for the calendar? Did Eudemus mention
these calculations outside the quoted passage? There is a definite answer to the
last of these questions. In Eudemus’ report, Callippus mentions Meton’s and
Euctemon’s calculations as something already familiar, without citing any nu-
merical data; Eudemus had obviously already discussed the matter. In Eude-
mus’ time, the problem of the irregularity of the heavenly bodies’ movements
played so important a role that he could hardly have passed over the
pro¯toi
heuretai of this fact in silence, even if they themselves had failed to come to the
conclusions that would be drawn from their discoveries a hundred years later.
The logic of the development of science, as Aristotle understood it, allows us to
discern in the discoveries of the past what their authors could not conceive
of.
177
Still, one can attribute to Eudemus such an interpretation of Meton and
Euctemon’s discovery only by admitting that the level of their knowledge was
insufficient to account for the solar anomaly by the varying speed of its motion,
as it was later suggested by Callippus.
Though the fragments of Meton and Euctemon still have not been collected,
which they certainly deserve, even the sundry evidence of their astronomical
studies testifies, along with the reconstruction of Euctemon’s parapegma,
178
to
the latter called him ‘Thales’ and associated him with the quadrature of the circle;
cf. Plut.