1 The Birth of Science - MSRI

274 10. Lost Science
Ptolemy says, in the passage where he denies that Hipparchus had taken
steps toward a planetary theory:
All that he did was to make a compilation of the data arranged in a
more useful way[.] 158
Fitting a theory to a great deal of experimental data of course requires a
lot of data reorganization, and these manipulations were not intelligible
to imperial-age scholars, who no longer created theories based on experimental
data, but at best used them. In Ptolemy’s time it was thought that
a theory must be put forth in a purely deductive fashion; Ptolemy’s exposition
is of this type and we have seen that Galen criticized Herophilus’
treatment of heartbeats for the same reason. 159
The preceding discussion suggests that the guiding ideas that we have
descried in Hipparchus’ astronomy did not remain at a qualitative stage,
but that, on their basis, a quantitative description of planetary motions
was begun. This conjecture finds support in Seneca’s statement that “we
have recently started to understand” the motions of the planets, in a statement
of Pliny that seems to imply that the study of Mars’ motion had
been particularly difficult, 160 and in Ptolemy’s report of Hipparchus’ dissatisfaction
with the incomplete accord between theory and experimental
data. 161
Theon of Smyrna, a contemporary of Ptolemy, wrote:
[The sun] is the place that animates the cosmos, as cosmos and living page 342
being — as if, blazing-hot, it were the heart of the universe, because
of motion and magnitude and the common journey of all that is
around it. . . .
The center of the magnitude is the earthly, cold and immobile one;
but the center that animates the cosmos, as universe and as living
being, is that of the sun, which is said to be the heart of the universe
and the place whence derives the universe’s soul, which reaches out
all the way to its edge. 163
These two notions — the particular role of the sun in animating the world
and the existence of a “cosmic sympathy” between heavenly bodies — sur-
158
Ptolemy, Syntaxis mathematica, IX, ii, 210 (ed. Heiberg), Toomer translation.
159
See page 132.
160
“Multa promi amplius circa haec possunt secreta naturae legesque, quibus ipsa serviat, exempli
gratia in Martis sidere, cuius est maxime inobservabilis cursus[.]” (Pliny, Naturalis historia, II,
77). Note that Pliny’s sources used the concept of “laws of nature” and expressed it in the same
terminology that was transmitted down to the modern age (in part by writers like Pliny).
161
Ptolemy, Syntaxis mathematica, IX, ii, 210 (ed. Heiberg).
163
Theon of Smyrna, Expositio rerum mathematicarum ad legendum Platonem utilium, III, xxxiii = 187,
14–18 and 188, 2–7 (ed. Hiller).
Revision: 1.11 Date: 2003/01/06 02:20:46