processes, fits with Geminus’ own procedure in the Introductio and is reflected in later
Stoicizing literature, notably K’ astronomical handbook.
In particular, this Poseido ̄nian passage may illuminate the relation between the Introductio
and the Calendar (or parape ̄gma), appended in the MSS. The Calendar lists for a complete
year those days on which, according to specified authorities, certain constellations rise
or set or cross the meridian. It begins with the winter solstice, and proceeds by zodiacal
month (i.e., the time the Sun takes to go through a given zodiacal sign or 30 ̊-segment
of the ecliptic that is named after a zodiacal constellation). Added to these stellar phe-
nomena are statements about the winds and rains that begin or stop. Some scholars today
deny Geminus’ authorship of the Calendar, but alleged disparities between the Introductio
and the Calendar can be effectively resolved by considering the purpose and scope of the
Introductio.
So while in §17 Geminus may attack the very idea of a calendar, his key target is non-
experts (e.g., his students and readers) who assume that the stellar risings and settings are the
causes of the meteorological phenomena associated with them. In this chapter, he not only
takes such risings and settings simply as signs correlated with the meteorological phenomena
through sustained observation, but shows that he regards such correlations as true only “for
the most part,” while urging that for surer predictive knowledge of the weather astronomers
should develop calendars based on causes rooted in natural processes. The Introductio
thus confirms that the traditional calendar is a legitimate part of astronomy, although
lacking the certainty that Geminus identifies as the goal of astronomical theorizing, and
regards as attained, for example, in the prediction of eclipses. Moreover, Geminus respects
Poseido ̄nios’ position on the relation between astronomy and natural philosophy by assign-
ing greater cognitive value to meteorological predictions based on a theory of natural causes
than to predictions based on observed correlations. Geminus may, therefore, be legitimately
labeled a post-Poseidonian Stoic, since for him those predictions based on physical caus-
ation, where the Sun is the leading cause, supersede predictive correlations based solely on
observation.
Ed.: G. Aujac, Géminos: Introduction aux phénomènes (CUF 1975).
Heath (1921) 2.222–231; Neugebauer (1975) 578–589; Alan C. Bowen and B.R. Goldstein, “Geminus
and the concept of mean motion in Greco-Latin astronomy,” AHES 50 (1996) 157–185; CTC 8
(2003) 7–48, Robert B. Todd; J. Evans and J.L. Berggren, Geminos’s Introduction to the Phenomena: A
Translation and Study of a Hellenistic Survey of Astronomy (2007).
Alan C. Bowen and Robert B. Todd
Gennadios (250 BCE – 95 CE)
A P., in G CMLoc 4.7 (12.760 K.), records his collyrium of
antimony, copper flakes (D 5.78–79), psimuthion, gum acacia, myrrh, and
opium in rainwater.
Fabricius (1726) 167.
PTK
Genthios, King of Illyria (180 – 168 BCE)
Son of King Pleuratos and Eurudike ̄, bribed into alliance with Perseus of Macedon
against Rome in 169/168 BCE, and taken captive: Livy 43.19–20, 44.23, 27, 29–30.
GENTHIOS, KING OF ILLYRIA