Sosigenes the Peripatetic ( grc-gre, Σωσιγένης) was a

philosopher A philosopher is a person who practices or investigates philosophy. The term ''philosopher'' comes from the grc, φιλόσοφος, , translit=philosophos, meaning 'lover of wisdom'. The coining of the term has been attributed to the Greek th ...

living at the end of the 2nd century AD. He was the tutor of Alexander of Aphrodisias and wrote a work ''On Revolving Spheres'', from which some important extracts have been preserved in Simplicius's commentary on

Aristotle Aristotle (; grc-gre, Ἀριστοτέλης ''Aristotélēs'', ; 384–322 BC) was a Greek philosopher and polymath during the Classical period in Ancient Greece. Taught by Plato, he was the founder of the Peripatetic school of phil ...

's '' De Caelo''.

Work

Sosigenes criticized both

and Eudoxus for their imperfect theory of celestial spheres and also the use of epicycles, which he felt to be inconsistent with Aristotle's philosophical postulates. He pointed out that the

planets A planet is a large, rounded astronomical body that is neither a star nor its remnant. The best available theory of planet formation is the nebular hypothesis, which posits that an interstellar cloud collapses out of a nebula to create a young ...

varied markedly in brightness, and that

solar eclipse A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby obscuring the view of the Sun from a small part of the Earth, totally or partially. Such an alignment occurs during an eclipse season, approximately every six month ...

s are sometimes

total Total may refer to: Mathematics * Total, the summation of a set of numbers * Total order, a partial order without incomparable pairs * Total relation, which may also mean ** connected relation (a binary relation in which any two elements are comp ...

and sometimes annular, suggesting that the distances between the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

and

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

were not the same at different eclipses. Sosigenes is perhaps called "the

Peripatetic Peripatetic may refer to: *Peripatetic school, a school of philosophy in Ancient Greece *Peripatetic axiom * Peripatetic minority, a mobile population moving among settled populations offering a craft or trade. *Peripatetic Jats There are several ...

" only because of his connection with Alexander. Some ancient evidence may be taken to suggest that he was, in fact, a

Stoic Stoic may refer to: * An adherent of Stoicism; one whose moral quality is associated with that school of philosophy *STOIC, a programming language * ''Stoic'' (film), a 2009 film by Uwe Boll * ''Stoic'' (mixtape), a 2012 mixtape by rapper T-Pain *' ...

. As John Patrick Lynch has written:

The other two teachers of Alexander may actually have been the philosophers whom ancient sources called Stoics; in both cases, Herminos/Sosigenes "the Stoic" have been distinguished from Herminos/Sosigenes "the Peripatetic" only on the grounds that the two latter men were teachers of Alexander of Aphrodisias. But it is not improbable that Alexander of Aphrodisias studied with two Stoic teachers and that these two pairs of homonymous contemporaries are actually only two Stoic philosophers.John Patrick Lynch, ''Aristotle's School: A Study of a Greek Educational Institution'', Berkeley: University of California Press, 1972, p. 215.

He is often confused with the astronomer

Sosigenes of Alexandria Sosigenes ( grc-gre, Σωσιγένης) was an ancient astronomer. According to Pliny the Elder's '' Natural History'' 18.210–212, Julius Caesar consulted him while he was designing the Julian calendar. Biography Little is known about him a ...

, who advised

Julius Caesar Gaius Julius Caesar (; ; 12 July 100 BC – 15 March 44 BC), was a Roman general and statesman. A member of the First Triumvirate, Caesar led the Roman armies in the Gallic Wars before defeating his political rival Pompey in a civil war, and ...

on the reform of the

Roman calendar The Roman calendar was the calendar used by the Roman Kingdom and Roman Republic. The term often includes the Julian calendar established by the reforms of the Roman dictator, dictator Julius Caesar and Roman emperor, emperor Augustus in the ...

Notes

References

*Irby-Massie G., Keyser P., ''Greek Science of the Hellenistic Era: A Sourcebook'', pages 80–81. Routledge. *Zhmud L., Chernoglazov A., (translator), ''The Origin of the History of Science in Classical Antiquity'', page 231. Walter de Gruyter. * {{DEFAULTSORT:Sosigenes The Peripatetic 2nd-century Greek philosophers Ancient Greek astronomers Roman-era Peripatetic philosophers Roman-era Greeks Roman-era philosophers in Athens