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

pro¯toi heuretai to the already se-
lected astronomical material from which physics had been removed in advance.
Aristotle’s notions, first set forth in his
Physics (193b 22–194a 11), of
boundaries between the two closely related sciences are certainly represen-
tative of the way mathematical astronomers of the fourth century understood
their own subject.
90
In
De caelo and the other works, Aristotle regularly refers
to the expert knowledge of the
mathe¯matikoi;
91
in
Met. 1073b 18f., he ex-
plicitly names Eudoxus and Callippus and develops their ideas. It seems very
probable that the ‘mathematicians’ figuring in
De caelo are none other than
Eudoxus and his pupils, from whom Aristotle derived data of the sizes of
heavenly bodies and distances between them, their velocities, the length of the
earth’s circumference, etc.
92
No less decisive was the influence of Eudoxus and
90
Elsewhere Aristotle says that nautik3 @strología, descriptive (and practical), es-
tablishes empirical facts, while maqhmatik3 @strología explains them (APo 78b
36f., see above, 73 n. 119). The line is drawn, accordingly, between Ôti and dióti;
mathe¯matikoi, moreover, may not know the particular facts. The latter thesis seem to
come from Aristotle himself, rather than from
 mathe¯matikoi, who sought expla-
nations consistent with observed data. Geminus’ definition of astronomy (Procl.
 In
Eucl., 41.19f.) coincides practically with that of Aristotle: a science, closely related
to physics, on heavenly bodies’ motions, their sizes and shapes, their distances from
earth and respective brightness, etc.
91
Cael. 291a 29f., b 9, 297a 2f., 298a 15; see also PA 639b 7f., Met. 1073b 3f., Mete.
345a 36f.
92
Lasserre printed the references from
De caelo as testimonies on Eudoxus (Eudoxos
D 7, 10–11).

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3. Physical and mathematical astronomies
251
his school on defining what is the subject of mathematical astronomy and pre-
cisely how it differs from physics. By this I mean not any formal definitions of
astronomy, but the practices it had been following and the further course of its
development. A pronounced tendency to develop astronomy by mathematical
methods, while taking empirical data (fainómena) fully into account, is a dis-
tinctive feature of Eudoxus’ school. The celestial kinematics of Eudoxus and
Callippus abstracted from the physical nature of heavenly bodies and explained
their movements by means of mathematical models.
93
In the next generation,
this tendency was reinforced by Autolycus and Euclid, who regarded astron-
omy as spherical geometry and applied their kinematic models to heavenly
bodies’ movements.
In his
History of Astronomy, Eudemus considered the past from the stand-
point of the mathematical astronomy of the late fourth century and selected ma-
terial in accordance with its professional criteria. Conceived in this way, the
history of astronomy included Thales’ studies of solstices, Anaximander’s the-
ory of the sizes of heavenly bodies, the Pythagorean order of the planets, the es-
timate of the obliquity of the ecliptic by Oenopides, Eudoxus’ program of ‘sav-
ing the phenomena’, and much else. It did not include the questions that con-
temporary astronomers left to the physicists (e.g., what does the sun consist
of?), nor answers irrelevant to their science (e.g., Anaximander’s explanation
of eclipses). The second criterion of the selection of material – the search for
discoveries that constituted an integral part of contemporary astronomy or
could be treated as a stage in its progress – worked in the same direction as the
first one, narrowing the factual scope of the