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Posidonius



 
 
Posidonius (Greek
Greek language

Greek is an Indo-European languages native to the southern Balkan peninsula, the language of the Greek people. It forms an independent branch within Indo-European....
: ??se?d????? / Poseidonios) "of Apameia
Apamea (Syria)

Apamea or Apameia was a treasure city and stud-depot of the Seleucid kings, was capital of Apamene, on the right bank of the Orontes River....
" (? ?paµe??) or "of Rhodes
Rhodes

Rhodes is a Greece List of islands of Greece approximately southwest of Turkey in eastern Aegean Sea. It is the largest of the Dodecanese islands in terms of both land area and population, with a population of 117,007 of which 53,709 resided in the Rhodes capital city of the island....
" (? ??d???) (ca. 135 BCE - 51 BCE), was a Greek
Greeks

The Greeks , also known as Hellenes, are a nation and ethnic group native to Greece, Cyprus and neighbouring regions, who can also be found in Greek diaspora communities around the world....
 Stoic
STOIC

STOIC was a variant of Forth .It started out at the MIT and Harvard Biomedical Engineering Centre in Boston, and was written in February 1977 by Jonathan Sachs....
 philosopher, politician
Politician

A politician is an individual who is involved in influencing public decision making through the influence of politics or a person who influences the way a society is governed....
, astronomer
Astronomer

An astronomer is a scientist who studies Celestial body such as planets, stars, and Galaxy.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using physical laws....
, geographer
Geographer

A geographer is a scientist whose area of study is geography, the study of Earth's physical natural environment and human habitat .Though geographers are historically known as people who make maps, map making is actually the field of study of cartography, a subset of geography....
, historian
Historian

A historian is an individual who studies and writes about history, and is regarded as an authority on it. Historians are concerned with the continuous, systematic narrative and research of past events as relating to the human race; as well as the study of all events in time....
 and teacher
Teacher

In education, a teacher is a person who teaches. A teacher who teaches an individual student may also be described as a personal tutor.The role of teacher is often formal and ongoing, carried out by way of Occupation or Profession at a school or other place of formal education....
 native to Apamea
Apamea

Apamea or Apameia is the name of several Hellenistic cities in western Asia, after Apama, the wife of Seleucus I Nicator:*Apamea , on the Orontes River, northwest of Hama, Syria...
, Syria
History of Syria

This article deals with the history of Syria, and the nations previously occupying its territory....
. He was acclaimed as the greatest polymath
Polymath

A polymath is a person whose knowledge is not restricted to one subject area. In less formal terms, a polymath may simply refer to someone who is very knowledgeable....
 of his age. None of his vast body of work can be read in its entirety today, as it exists only in fragments.

donius, nicknamed "the Athlete", was born to a Greek
Greeks

The Greeks , also known as Hellenes, are a nation and ethnic group native to Greece, Cyprus and neighbouring regions, who can also be found in Greek diaspora communities around the world....
 family in Apamea
Apamea (Syria)

Apamea or Apameia was a treasure city and stud-depot of the Seleucid kings, was capital of Apamene, on the right bank of the Orontes River....
, a Hellenistic city on the river Orontes in northern Syria
Syria

Syria , officially the Syrian Arab Republic , is an Arab-majority country in Southwest Asia, bordering Lebanon and the Mediterranean Sea to the west, Israel to the southwest, Jordan to the south, Iraq to the east, and Turkey to the north....
, and probably died in Rome
Rome

Rome is the capital city of Italy and Lazio, and is Italy's largest and most populous city, with 2,724,347 residents in an urban area of some ....
 or Rhodes
Rhodes

Rhodes is a Greece List of islands of Greece approximately southwest of Turkey in eastern Aegean Sea. It is the largest of the Dodecanese islands in terms of both land area and population, with a population of 117,007 of which 53,709 resided in the Rhodes capital city of the island....
.

Posidonius completed his higher education in Athens
Athens

Athens , the Capital and largest city of Greece, dominates the Attica periphery; as one of the List of cities by time of continuous habitation, its recorded history spans around 3,400 years....
, where he was a student of the aged Panaetius
Panaetius

Panaetius of Rhodes, , was a Stoic philosopher. He was a pupil of Diogenes of Babylon and Antipater of Tarsus in Athens, before travelling with his friend Scipio Aemilianus Africanus to Rome where he did much to introduce Stoic doctrines to the city....
, the head of the Stoic
STOIC

STOIC was a variant of Forth .It started out at the MIT and Harvard Biomedical Engineering Centre in Boston, and was written in February 1977 by Jonathan Sachs....
 school.

He settled around 95 BCE in Rhodes, a maritime state which had a reputation for scientific research, and became a citizen.

hodes, Posidonius actively took part in political life, and his high standing is apparent from the offices he held.






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Posidonius (Greek
Greek language

Greek is an Indo-European languages native to the southern Balkan peninsula, the language of the Greek people. It forms an independent branch within Indo-European....
: ??se?d????? / Poseidonios) "of Apameia
Apamea (Syria)

Apamea or Apameia was a treasure city and stud-depot of the Seleucid kings, was capital of Apamene, on the right bank of the Orontes River....
" (? ?paµe??) or "of Rhodes
Rhodes

Rhodes is a Greece List of islands of Greece approximately southwest of Turkey in eastern Aegean Sea. It is the largest of the Dodecanese islands in terms of both land area and population, with a population of 117,007 of which 53,709 resided in the Rhodes capital city of the island....
" (? ??d???) (ca. 135 BCE - 51 BCE), was a Greek
Greeks

The Greeks , also known as Hellenes, are a nation and ethnic group native to Greece, Cyprus and neighbouring regions, who can also be found in Greek diaspora communities around the world....
 Stoic
STOIC

STOIC was a variant of Forth .It started out at the MIT and Harvard Biomedical Engineering Centre in Boston, and was written in February 1977 by Jonathan Sachs....
 philosopher, politician
Politician

A politician is an individual who is involved in influencing public decision making through the influence of politics or a person who influences the way a society is governed....
, astronomer
Astronomer

An astronomer is a scientist who studies Celestial body such as planets, stars, and Galaxy.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using physical laws....
, geographer
Geographer

A geographer is a scientist whose area of study is geography, the study of Earth's physical natural environment and human habitat .Though geographers are historically known as people who make maps, map making is actually the field of study of cartography, a subset of geography....
, historian
Historian

A historian is an individual who studies and writes about history, and is regarded as an authority on it. Historians are concerned with the continuous, systematic narrative and research of past events as relating to the human race; as well as the study of all events in time....
 and teacher
Teacher

In education, a teacher is a person who teaches. A teacher who teaches an individual student may also be described as a personal tutor.The role of teacher is often formal and ongoing, carried out by way of Occupation or Profession at a school or other place of formal education....
 native to Apamea
Apamea

Apamea or Apameia is the name of several Hellenistic cities in western Asia, after Apama, the wife of Seleucus I Nicator:*Apamea , on the Orontes River, northwest of Hama, Syria...
, Syria
History of Syria

This article deals with the history of Syria, and the nations previously occupying its territory....
. He was acclaimed as the greatest polymath
Polymath

A polymath is a person whose knowledge is not restricted to one subject area. In less formal terms, a polymath may simply refer to someone who is very knowledgeable....
 of his age. None of his vast body of work can be read in its entirety today, as it exists only in fragments.

Life

Posidonius, nicknamed "the Athlete", was born to a Greek
Greeks

The Greeks , also known as Hellenes, are a nation and ethnic group native to Greece, Cyprus and neighbouring regions, who can also be found in Greek diaspora communities around the world....
 family in Apamea
Apamea (Syria)

Apamea or Apameia was a treasure city and stud-depot of the Seleucid kings, was capital of Apamene, on the right bank of the Orontes River....
, a Hellenistic city on the river Orontes in northern Syria
Syria

Syria , officially the Syrian Arab Republic , is an Arab-majority country in Southwest Asia, bordering Lebanon and the Mediterranean Sea to the west, Israel to the southwest, Jordan to the south, Iraq to the east, and Turkey to the north....
, and probably died in Rome
Rome

Rome is the capital city of Italy and Lazio, and is Italy's largest and most populous city, with 2,724,347 residents in an urban area of some ....
 or Rhodes
Rhodes

Rhodes is a Greece List of islands of Greece approximately southwest of Turkey in eastern Aegean Sea. It is the largest of the Dodecanese islands in terms of both land area and population, with a population of 117,007 of which 53,709 resided in the Rhodes capital city of the island....
.

Posidonius completed his higher education in Athens
Athens

Athens , the Capital and largest city of Greece, dominates the Attica periphery; as one of the List of cities by time of continuous habitation, its recorded history spans around 3,400 years....
, where he was a student of the aged Panaetius
Panaetius

Panaetius of Rhodes, , was a Stoic philosopher. He was a pupil of Diogenes of Babylon and Antipater of Tarsus in Athens, before travelling with his friend Scipio Aemilianus Africanus to Rome where he did much to introduce Stoic doctrines to the city....
, the head of the Stoic
STOIC

STOIC was a variant of Forth .It started out at the MIT and Harvard Biomedical Engineering Centre in Boston, and was written in February 1977 by Jonathan Sachs....
 school.

He settled around 95 BCE in Rhodes, a maritime state which had a reputation for scientific research, and became a citizen.

Political offices

In Rhodes, Posidonius actively took part in political life, and his high standing is apparent from the offices he held. He attained the highest public office as one of the prytaneis
Prytaneis

The Prytaneis were the executives of the Boule of ancient Athens. The term is probably of pre-Ancient Greece origin, possibly cognate to Etruscan language pruni....
 (presidents, having a six months tenure) of Rhodes. He served as an ambassador to Rome in 87 - 86 BCE, during the Marian
Gaius Marius

Gaius Marius was a Roman Republic general and politician elected consul an unprecedented seven times during his career. He was also noted for his dramatic Marian Reforms of Roman legion, authorizing recruitment of landless citizens and reorganizing the structure of the legions into separate Cohort ....
 and Sullan
Lucius Cornelius Sulla

Lucius Cornelius Sulla Felix , or simply Sulla, was a Roman general and politician, holding the office of consul twice as well as the Roman dictator....
 era.

Along with other Greek intellectuals, Posidonius favored Rome as the stabilizing power in a turbulent world. His connections to the Roman ruling class was for him not only politically important and sensible but was also important to his scientific researches. His entry into the highest government circles enabled Posidonius to undertake his travels into the west beyond the borders of Roman control, which, for a Greek traveler, would have been impossible without such Roman support.

Travels

After he had established himself in Rhodes, Posidonius made one or more journeys traveling throughout the Roman world and even beyond its boundaries to conduct scientific research. He traveled in Greece
Greece

Greece , officially the Hellenic Republic , is a country in southeastern Europe, situated on the southern end of the Balkans. It has borders with Albania, Bulgaria and the former Yugoslav Republic of Macedonia to the north, and Turkey to the east....
, Hispania
Hispania

Hispania was the name given by the Ancient Rome to the whole of the Iberian Peninsula . When Rome was a Roman Republic, Hispania was divided into Roman provinces: Hispania Citerior and Hispania Ulterior....
, Africa
Africa

Africa is the world's second-largest and second most-populous continent, after Asia. At about 30.2 million km? including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area....
, Italy
Italy

Italy , officially the Italian Republic , is a country located on the Italian Peninsula in Southern Europe and on the two largest islands in the Mediterranean Sea, Sicily and Sardinia....
, Sicily
Sicily

Sicily is an Autonomous regions with special statute of Italy. Of all the regions of Italy, Sicily covers the largest land area at 25,708 km? and currently has just over five million inhabitants....
, Dalmatia
Dalmatia

Dalmatia is a region on the eastern coast of the Adriatic Sea, situated mostly in modern Croatia and spreading between the island of Rab in the northwest and the Bay of Kotor in the southeast....
, Gaul
Gaul

Gaul is the name used for the region of Western Europe comprising part of present day northern Italy, France, Belgium, western Switzerland and the parts of the Netherlands and Germany on the west bank of the River Rhine....
, Liguria
Liguria

Liguria is a coastal Regions of Italy of north-western Italy, the third smallest of the Italian regions. Its capital is Genoa. It is a popular region with tourists for its beautiful beaches, picturesque little towns, and food....
, North Africa
North Africa

North Africa or Northern Africa is the northernmost region of the African continent, separated by the Sahara from Sub-Saharan Africa.Geopolitically, the United Nations subregion of Northern Africa includes the following seven countries or territories:...
, and on the eastern shores of the Adriatic.

In Hispania, on the Atlantic coast at Gades (the modern Cadiz
Cádiz

C?diz is a city and port in southwestern Spain. It is the capital of the province of C?diz, one of eight which make up the Autonomous communities of Spain of Andalusia....
), Posidonius studied the tides. He observed that the daily tides were connected with the orbit and the monthly tides with the cycles of the Moon
Moon

The Moon is Earth's only natural satellite and the List of natural satellites by diameter satellite in the Solar System. The average centre-to-centre distance from the Earth to the Moon is km, about thirty times the diameter of the Earth....
, and he hypothesized about the connections of the yearly cycles of the tides with the equinoxes and solstices.

In Gaul, he studied the Celt
Celt

Celts , is a modern term used to describe any of the European peoples who spoke, or speak, a Celtic languages. The term is also used in a wider sense to describe the Modern Celts of those peoples, notably those who participate in a Celtic culture....
s. He left vivid descriptions of things he saw with his own eyes while among them: men who were paid to allow their throats to be slit for public amusement and the nailing of skulls as trophies to the doorways. But he noted that the Celts honored the Druids, whom Posidonius saw as philosophers, and concluded that even among the barbaric 'pride and passion give way to wisdom, and Ares stands in awe of the Muses'. Posidonius wrote a geographic treatise on the lands of the Celt
Celt

Celts , is a modern term used to describe any of the European peoples who spoke, or speak, a Celtic languages. The term is also used in a wider sense to describe the Modern Celts of those peoples, notably those who participate in a Celtic culture....
s which has since been lost, but which has been assumed to be one of the sources for Tacitus
Tacitus

Publius Cornelius Tacitus was a Roman Senate and a historian of the Roman Empire. The surviving portions of his two major works—the Annals and the Histories —examine the reigns of the Roman Emperors Tiberius, Claudius, Nero and those that reigned in the Year of the Four Emperors....
' Germania
Germania (book)

The Germania , written by Tacitus around 98, is an ethnography work on the Germanic tribes outside the Roman Empire.This work survived only in one single manuscript that was found in Hersfeld Abbey, Holy Roman Empire and brought to Italy in 1455 where Enea Silvio Piccolomini, the later Pope Pius II, first examined and analyzed it, wher...
.

School

Posidonius's extensive writings and lectures gave him authority as a scholar and made him famous everywhere in the Graeco-Roman world, and a school grew around him in Rhodes. His grandson Jason
Jason of Nysa

Jason of Nysa, Anatolia, a Stoic philosopher, son of Menecrates, and, on his mother's side, grandson of Posidonius, of whom also he was the disciple and successor at the Stoic school at Rhodes....
, who was the son of his daughter and Menekrates of Nysa
Nysa, Anatolia

Nysa was an ancient Ancient Greece city of Anatolia, whose remnants are now in the Sultanhisar district of Aydin Province of Turkey 50 km east of the Ionian city of Ephesus....
, followed in his footsteps and continued Posidonius's school in Rhodes. Although little is known of the organization of his school, it is clear that Posidonius had a steady stream of Greek and Roman students.

Partial scope of writings

Posidonius was celebrated as a polymath
Polymath

A polymath is a person whose knowledge is not restricted to one subject area. In less formal terms, a polymath may simply refer to someone who is very knowledgeable....
 throughout the Greco-Roman world because he came near to mastering all the knowledge of his time, similar to Aristotle
Aristotle

Aristotle was a Greeks philosopher, a student of Plato and teacher of Alexander the Great. He wrote on many subjects, including physics, metaphysics, Poetics , theater, music, logic, rhetoric, politics, government, ethics, biology and zoology....
 and Eratosthenes
Eratosthenes

Eratosthenes of Cyrene was a Greeks mathematician, poet, sportsperson, geographer and astronomer. He made several discoveries and inventions including a system of latitude and longitude....
. He attempted to create a unified system for understanding the human intellect and the universe which would provide an explanation of and a guide for human behavior.

Posidonius wrote on physics
Physics

Physics is the natural science which examines basic concepts such as energy, force, and spacetime and all that derives from these, such as mass, charge, matter and its Motion ....
 (including meteorology
Meteorology

Meteorology is the interdisciplinary scientific study of the Earth's atmosphere that focuses on weather processes and forecasting . Studies in the field stretch back millennia, though significant progress in meteorology did not occur until the eighteenth century....
 and physical geography
Physical geography

Physical geography is one of the three major subfields of geography. Physical geography focuses on understanding the processes and patterns in the natural environment, as opposed to the cultural or built environment, the domain of human geography....
), astronomy
Astronomy

Astronomy is the science of Astronomical object and Phenomenon that originate outside the Earth's atmosphere . It is concerned with the evolution, physics, chemistry, meteorology, and motion of celestial objects, as well as the physical cosmology....
, astrology
Astrology

Astrology is a group of systems, traditions, and beliefs which hold that the relative positions of astronomical object and related details can provide useful information about personality, human affairs, and other terrestrial matters....
 and divination
Divination

Divination is the attempt to gain insight into a question or situation by way of a standardized process or ritual. Diviners ascertain their interpretations of how a querent should proceed by reading signs, events, or omens, or through alleged contact with a supernatural agency....
, seismology
Seismology

Seismology is the scientific study of earthquakes and the propagation of Linear elasticity#Elastic waves through the Earth. The field also includes studies of earthquake effects, such as tsunamis as well as diverse seismic sources such as volcanic, tectonic, oceanic, atmospheric, and artificial processes ....
, geology
Geology

Geology is the science and study of the solid and liquid matter that constitute the Earth. The field of geology encompasses the study of the composition, structural geology, physical properties, dynamics, and History of the Earth of Earth materials, and the processes by which they are formed, moved, and changed....
 and mineralogy
Mineralogy

Mineralogy is an Earth Science focused around the chemistry, crystal structure, and physical properties of minerals. Specific studies within mineralogy include the processes of mineral origin and formation, classification of minerals, their geographical distribution, as well as their utilization....
, hydrology
Hydrology

Hydrology is the study of the movement, distribution, and quality of water throughout the Earth, and thus addresses both the hydrologic cycle and water resources....
, botany
Botany

Botany, plant science, phytology, or plant biology is a branch of biology and is the Scientific method of plant life and development....
, ethics
Ethics

Ethics is a word for a philosophy that encompasses proper conduct and good living. It is significantly broader than the common conception of ethics as the analyzing of right and wrong....
, logic
Logic

Logic is the study of the principles of valid demonstration and inference. Logic is a branch of philosophy, a part of the classical Trivium . The word derives from Greek language ?????? , fem....
, mathematics
Mathematics

Mathematics is the study of quantity, structure, space, change, and related topics of pattern and form. Mathematicians seek out patterns whether found in numbers, space, natural science, computers, imaginary abstractions, or elsewhere....
, history
HIStory

HIStory: Past, Present and Future, Book I is a double album by Michael Jackson, released on June 20, 1995, and is Jackson's ninth. The first disc, named "HIStory Begins" consists of a selection of Jackson's greatest hits from the singer's past fifteen years, while the second, named "HIStory Continues" features new songs, with the...
, natural history
Natural history

Natural history is the scientific research of plants or animals, leaning more towards the observational than experimental methods of study, and encompasses more research that is published in magazines than in academic journals....
, anthropology
Anthropology

Anthropology is the study of humans and humanity in its totality. Anthropology has origins in the natural sciences, and the humanities. In Great Britain it was originally divided into physical anthropology and cultural anthropology, which itself was divided into archaeology, technology, ethnology and sociology ....
, and tactics. His studies were major investigations into their subjects, although not without errors.

None of his works survive intact. All that we have found are fragments, although the titles and subjects of many of his books are known.

Philosophy
For Posidonius, philosophy was the dominant master art and all the individual sciences were subordinate to philosophy, which alone could explain the cosmos. All his works, from scientific to historical, were inseparably philosophical.

He accepted the Stoic categorization of philosophy into physics (natural philosophy, including metaphysics and theology), logic (including dialectic), and ethics. These three categories for him were, in Stoic fashion, inseparable and interdependent parts of an organic, natural whole. He compared them to a living being, with physics the meat and blood, logic the bones and tendons which held the organism together, and ethics – the most important part – the soul. His philosophical grand vision was that the universe itself was similarly interconnected, as if an organism, through cosmic "sympathy", in all respects from the development of the physical world to the history of humanity.

Although a firm Stoic, Posidonius was, like Panaetius and other Stoics of the middle period, eclectic. He followed not only the older Stoics, but Plato
Plato

Plato , was a Classical Greece Greeks philosopher, mathematician, writer of philosophical dialogues, and founder of the Platonic Academy in Ancient Athens, the first institution of higher learning in the western world....
 and Aristotle
Aristotle

Aristotle was a Greeks philosopher, a student of Plato and teacher of Alexander the Great. He wrote on many subjects, including physics, metaphysics, Poetics , theater, music, logic, rhetoric, politics, government, ethics, biology and zoology....
. Although it is not certain, Posidonius may have written a commentary on Plato's Timaeus
Timaeus

Timaeus is a Greek name, meaning "Honour". It may refer to:*Timaeus , a Socratic dialogue by Plato*Timaeus of Locri, the 5th-century Pythagorean philosopher, appearing in Plato's dialogue...
.

He was the first Stoic to depart from the orthodox doctrine that passions were faulty judgments and posit that Plato's view of the soul had been correct, namely that passions were inherent in human nature. In addition to the rational faculties, Posidonius taught that the human soul had faculties that were spirited (anger, desires for power, possessions, etc.) and desiderative (desires for sex and food). Ethics was the problem of how to deal with these passions and restore reason as the dominant faculty.

Posidonius upheld the Stoic doctrine of Logos
Logos

is an important term in philosophy, analytical psychology, rhetoric and religion.Heraclitus established the term in Western philosophy as meaning both the source and fundamental order of the cosmos....
, which ultimately passed into Judeo-Christian
Judeo-Christian

Judeo?Christian is a term used to describe the body of concepts and values which are thought to be held in common by Judaism and Christianity, and considered, often along with classical antiquity Greco-Roman civilization, a fundamental basis for Western world legal codes and moral values....
 belief. Posidonius also affirmed the Stoic doctrine of the future conflagration.

Physics
In Stoic physics, Posidonius advocated a theory of cosmic "sympathy" (sumpatheia), the organic interrelation of all appearances in the world, from the sky to the earth, as part of a rational design uniting humanity and all things in the universe, even those that were temporally and spatially separate. Although his teacher Panaetius had doubted divination, Posidonius used the theory of cosmic sympathy to support his belief in divination - whether through astrology or prophetic dreams - as a kind of scientific prediction.

Astronomy
Some fragments of his writings on astronomy survive through the treatise by Cleomedes
Cleomedes

Cleomedes was a Ancient Greece astronomer who is known chiefly for his book On the Circular Motions of the Celestial Bodies....
, On the Circular Motions of the Celestial Bodies, the first chapter of the second book appearing to have been mostly copied from Posidonius.

Posidonius advanced the theory that the Sun emanated a vital force which permeated the world.

He attempted to measure the distance and size of the Sun
Sun

The Sun , a G V star, is the star at the center of the Solar System. The Earth and other matter orbit the Sun, which by itself accounts for about 98.6% of the Solar System's mass....
. In about 90 BCE Posidonius estimated the astronomical unit
Astronomical unit

An astronomical unit is a unit of length based on the mean distance from the Earth to the Sun. The precise value of the AU is currently accepted as 149,597,870,691 Plus-minus sign 6 metres ....
 to be a0/rE = 9893, which was still too small by half. In measuring the size of the Sun, however, he reached a figure larger and more accurate than those proposed by other Greek astronomers and Aristarchus of Samos
Aristarchus of Samos

Aristarchus or Aristarch was a Greeks astronomer and mathematician, born on the island of Samos Island, in Greece. He was the first Greek, and the first man in general, to present an explicit argument for a Heliocentrism of the solar system, placing the Sun, not the Earth, at the center of the known universe....
.

Posidonius also calculated the size and distance of the Moon
Moon

The Moon is Earth's only natural satellite and the List of natural satellites by diameter satellite in the Solar System. The average centre-to-centre distance from the Earth to the Moon is km, about thirty times the diameter of the Earth....
.

Posidonius constructed an orrery
Orrery

File:orrery small.jpgAn orrery is a mechanical device that illustrates the relative positions and motions of the planets and natural satellites in the solar system in a heliocentric model....
, possibly similar to the Antikythera mechanism
Antikythera mechanism

The Antikythera mechanism , is an ancient mechanical calculator designed to calculate astronomy positions. It was discovered in the Antikythera wreck off the Greece island of Antikythera, between Kythera and Crete, in 1901....
. Posidonius's orrery, according to Cicero
Cicero

Marcus Tullius Cicero was a Ancient Rome philosopher, statesman, lawyer, political theorist, and Constitution of the Roman Republic. Cicero is widely considered one of Rome's greatest rhetoric and prose stylists....
, exhibited the diurnal motions of the sun, moon, and the five known planets.

Geography, ethnology and geology
Posidonius’s fame beyond specialized philosophical circles had begun, at the latest, in the eighties with the publication of the work "about the ocean and the adjacent areas". This work was not only an overall representation of geographical questions according to current scientific knowledge, but it served to popularize his theories about the internal connections of the world, to show how all the forces had an effect on each other and how the interconnectedness applied also to human life, to the political just as to the personal spheres. In this work, Posidonius detailed his theory of the effect on a people’s character by the climate, which included his representation of the "geography of the races". This theory was not solely scientific, but also had political implications -- his Roman readers were informed that the climatic central position of Italy was an essential condition of the Roman destiny to dominate the world. As a Stoic he did not, however, make a fundamental distinction between the civilized Romans as masters of the world and the less civilized peoples.

Posidonius measured the Earth
Earth

Earth is the third planet from the Sun. Earth is the largest of the terrestrial planets in the Solar System in diameter, mass and density. It is also referred to as the World and Wiktionary:Terra.Note that by International Astronomical Union convention, the term "Terra" is used for naming extensive land masses, rather...
's circumference by reference to the position of the star Canopus. As explained by Cleomedes, Posidonius observed Canopus on but never above the horizon at Rhodes, while at Alexandria
Alexandria

Alexandria , with a population of 4.1 million, is the second-largest city in Egypt, and is the country's largest seaport, serving about 80% of Egypt's imports and exports....
 he saw it ascend as far as 7 1/2 degrees above the horizon (the arc between the latitude of the two locales is actually 5 degrees 14 minutes). Since he thought Rhodes was 5,000 stadia due north of Alexandria, and the difference in the star's elevation indicated the distance between the two locales was 1/48th of the circle, he multiplied 5,000 by 48 to arrive at a figure of 240,000 stadia for the circumference of the earth. While translating stadia into modern units of distance is problematic, as an ancient stadium could measure anywhere from about 157 to around 211 meters, it is generally thought that the stadium used by Posidonius was almost exactly 1/10 of a modern statute mile, near the middle of the ancient range. Thus Posidonius' measure of 240,000 stadia translates to 24,000 miles, not much short of the actual circumference of 24,901 miles.

Posidonius was informed in his approach to finding the earth's circumference by Eratosthenes
Eratosthenes

Eratosthenes of Cyrene was a Greeks mathematician, poet, sportsperson, geographer and astronomer. He made several discoveries and inventions including a system of latitude and longitude....
, who a century earlier used the elevation of the sun at different latitudes to arrive at a figure of 250,000 stadia (which he rounded to 252,000 so that it would be divisible by 60). As with Posidonius, Eratosthenes' stadium is thought to have equated to 1/10th of a mile, so that his measure translates to 25,000 (or 25,200) miles. Both men's figures for the earth's circumference were uncannily accurate, aided in part in each case by mutually compensating errors in measurement. However, Posidonius later revised his original calculation by correcting the distance between Rhodes and Alexandria to 3,750 stadia, resulting in a circumference of 180,000 stadia, or 18,000 miles. Ptolemy
Ptolemy

Claudius Ptolemaeus , known in English as Ptolemy , was a Roman Greek mathematics, Greek astronomy, geographer and astrologer. He lived in History of Roman Egypt, and was probably born there in a town in the Thebaid called Ptolemais Hermiou; he died in Alexandria around 168 AD....
 discussed and favored this revised figure of Posidonius over Eratosthenes in his Geographia, and during the Middle Ages
Middle Ages

File:Karl 1 mit papst gelasius gregor1 sacramentar v karl d kahlen.jpgThe Middle Ages of European history are a period in history which lasted for roughly a millennium, commonly dated from the fall of the Roman Empire in the 5th century to the beginning of the Early Modern Period in the 16th century, marked by the division of Western Christi...
 scholars divided into two camps regarding the circumference of the earth, identified with Eratosthenes' calculation on the one hand and Posidonius' 180,000-stadium measure on the other.

Like Pytheas
Pytheas

Pytheas of Massilia , 4th century BC, was a Greece geography and exploration from the Greek colonies colony, Massilia . He made a voyage of exploration to northwestern Europe at about 325 BC....
, Posidonius believed the tide
Tide

Tides are the rising of Earth's ocean surface caused by the tidal forces of the Moon and the Sun acting on the oceans. Tides cause changes in the depth of the marine and estuary water bodies and produce oscillating currents known as tidal streams, making prediction of tides important for coastal navigation ....
 is caused by the Moon
Moon

The Moon is Earth's only natural satellite and the List of natural satellites by diameter satellite in the Solar System. The average centre-to-centre distance from the Earth to the Moon is km, about thirty times the diameter of the Earth....
. Posidonius was, however, wrong about the cause. Thinking that the Moon was a mixture of air and fire, he attributed the cause of the tides to the heat of the Moon, hot enough to cause the water to swell but not hot enough to evaporate it.

He recorded observations on both earthquakes and volcanoes, including accounts of the eruptions of the volcanoes in the Aeolian Islands
Aeolian Islands

The Aeolian Islands are a volcanic archipelago in the Tyrrhenian Sea north of Sicily. The locals residing on the islands are known as Eolian. They are a popular tourist destination in the summer, and attract up to 200,000 visitors annually....
, north of Sicily
Sicily

Sicily is an Autonomous regions with special statute of Italy. Of all the regions of Italy, Sicily covers the largest land area at 25,708 km? and currently has just over five million inhabitants....
.

Meteorology
Posidonius in his writings on meteorology followed Aristotle
Aristotle

Aristotle was a Greeks philosopher, a student of Plato and teacher of Alexander the Great. He wrote on many subjects, including physics, metaphysics, Poetics , theater, music, logic, rhetoric, politics, government, ethics, biology and zoology....
. He theorized on the causes of clouds, mist, wind, and rain as well as frost, hail, lightning, and rainbows.

Mathematics
In addition to his writings on geometry, Posidonius was credited for creating some mathematical definitions, or for articulating views on technical terms, for example 'theorem' and 'problem'.

History and tactics
In his Histories, Posidonius continued the World History of Polybius
Polybius

Polybius was a Greek historian of the Hellenistic Period noted for his book called The Histories covering in detail the period of 220–146 BC....
. His history of the period 146 - 88 BCE is said to have filled 52 volumes. His Histories continue the account of the rise and expansion of Roman dominance, which he appears to have supported. Posidonius did not follow Polybius's more detached and factual style, for Posidonius saw events as caused by human psychology; while he understood human passions and follies, he did not pardon or excuse them in his historical writing, using his narrative skill in fact to enlist the readers' approval or condemnation.

For Posidonius "history" extended beyond the earth into the sky; humanity was not isolated each in its own political history, but was a part of the cosmos. His Histories were not, therefore, concerned with isolated political history of peoples and individuals, but they included discussions of all forces and factors (geographical factors, mineral resources, climate, nutrition), which let humans act and be a part of their environment. For example, Posidonius considered the climate of Arabia and the life-giving strength of the sun, tides (taken from his book on the oceans), and climatic theory to explain people’s ethnic or national characters.

Of Posidonius's work on tactics, The Art of War, the Greek historian Arrian
Arrian

File:Flavius_Arrianus.jpgLucius Flavius Arrianus 'Xenophon , known in English as Arrian , and Arrian of Nicomedia, was a Ancient Rome historian , a public servant, a military commander and a philosopher of the Roman and Byzantine Greece period....
 complained that it was written 'for experts', which suggests that Posidonius may have had first hand experience of military leadership or, perhaps, utilized knowledge he gained from his acquaintance with Pompey
Pompey

Gnaeus Pompeius Magnus, commonly known as Pompey /'p?mpi/, Pompey the Great or Pompey the Triumvir , was a distinguished military and political leader of the late Roman Republic....
.

Reputation and influence

In his own era, his writings on almost all the principal divisions of philosophy made Posidonius a renowned international figure throughout the Graeco-Roman world and he was widely cited by writers of his era, including Cicero, Livy
Livy

Titus Livius , known as Livy in English language, was a Ancient Rome historian who wrote a monumental history of Rome, Ab Urbe Condita, from its founding through the reign of Augustus in Livy's own time....
, Plutarch
Plutarch

Lucius Mestrius Plutarchus , c. AD 46 ? 120 ? commonly known in English as Plutarch ? was a Ancient Rome historian , biographer, essayist, and Middle Platonism....
, Strabo
Strabo

Strabo was a Ancient Greeks history, geography and philosophy....
 (who called Posidonius "the most learned of all philosophers of my time"), Cleomedes, Seneca the Younger
Seneca the Younger

Lucius Annaeus Seneca was a Ancient Rome Stoicism philosopher, statesman, dramatist, and in one work humorist, of the Silver Age of Latin literature....
, Diodorus Siculus
Diodorus Siculus

Diodorus Siculus , was a Roman Greece historian who flourished in the 1st century BC. According to Diodorus' own work, he was born at Agira in Sicily ....
 (who used Posidonius as a source for his Bibliotheca historia ("Historical Library"), and others. Although his ornate and rhetorical style of writing passed out of fashion soon after his death, Posidonius was acclaimed during his life for his literary ability and as a stylist.

Posidonius was the major source of materials on the Celts of Gaul
Gaul

Gaul is the name used for the region of Western Europe comprising part of present day northern Italy, France, Belgium, western Switzerland and the parts of the Netherlands and Germany on the west bank of the River Rhine....
 and was profusely quoted by Timagenes
Timagenes

Timagenes was a Greek literature writer, historian and teacher of rhetoric. He came from Alexandria, was captured by Ancient Romes in 55 Before Christ and taken to Rome, where he was later set free....
, Julius Caesar
Julius Caesar

'Gaius Julius Caesar' , July 13, 100 BC ? March 15, 44 BC,) was a Roman Republic military and political leader. He played a critical role in the transformation of the Roman Republic into the Roman Empire....
, the Sicilian Greek Diodorus Siculus
Diodorus Siculus

Diodorus Siculus , was a Roman Greece historian who flourished in the 1st century BC. According to Diodorus' own work, he was born at Agira in Sicily ....
, and the Greek geographer Strabo
Strabo

Strabo was a Ancient Greeks history, geography and philosophy....
.

Posidonius appears to have moved with ease among the upper echelons of Roman society as an ambassador from Rhodes. He associated with some of the leading figures of late republican Rome, including Cicero and Pompey, both of whom visited him in Rhodes. In his twenties, Cicero attended his lectures (77 BCE) and they continued to correspond. Cicero in his De Finibus closely followed Posidonius's presentation of Panaetius's ethical teachings. Posidonius met Pompey when he was Rhodes's ambassador in Rome and Pompey visited him in Rhodes twice, once in 66 BCE during his campaign against the pirates and again in 62 BCE during his eastern campaigns, and asked Posidonius to write his biography. As a gesture of respect and great honor, Pompey lowered his fasces
Fasces

Fasces symbolize summary power and jurisdiction, and/or "strength through unity".The traditional ancient Rome fasces consisted of a bundle of white birch rods, tied together with a red leather ribbon into a cylinder, and often including a bronze axe amongst the rods, with the blade on the side, projecting from the bundle....
 before Posidonius's door. Other Romans who visited Posidonius in Rhodes were Velleius, Cotta, and Lucilius
Lucilius

Lucilius is the nomen of the gens Lucilia of ancient Rome.*Gaius Lucilius, satirist 2nd century BC. Lucilius was credited by Horace and others with originating the genre of satire....
.

Ptolemy
Ptolemy

Claudius Ptolemaeus , known in English as Ptolemy , was a Roman Greek mathematics, Greek astronomy, geographer and astrologer. He lived in History of Roman Egypt, and was probably born there in a town in the Thebaid called Ptolemais Hermiou; he died in Alexandria around 168 AD....
 was impressed by the sophistication of Posidonius's methods, which included correcting for the refraction of light passing through denser air near the horizon. Ptolemy's approval of Posidonius's result, rather than Eratosthenes's earlier and more correct figure, caused it to become the accepted value for the Earth's circumference for the next 1,500 years.

Posidonius fortified the Stoicism of the middle period with contemporary learning. Next to his teacher Panaetius, he did most, by writings and personal contacts, to spread Stoicism in the Roman world. A century later, Seneca referred to Posidonius as one of those who had made the largest contribution to philosophy.

His influence on philosophical thinking lasted until the Middle Ages
Middle Ages

File:Karl 1 mit papst gelasius gregor1 sacramentar v karl d kahlen.jpgThe Middle Ages of European history are a period in history which lasted for roughly a millennium, commonly dated from the fall of the Roman Empire in the 5th century to the beginning of the Early Modern Period in the 16th century, marked by the division of Western Christi...
, as is shown by citation in the Suda
Suda

The Suda or Souda is a massive 10th century Byzantine Empire Medieval Greek historical encyclopedia of the ancient Mediterranean world. It is an Encyclopedia lexicon with 30,000 entries, many drawing from ancient sources that have since been lost, and often derived from medieval Christian compilers....
, the massive medieval lexicon
Lexicon

In linguistics, the lexicon of a language is its vocabulary, including its words and expressions. More formally, it is a language's inventory of lexemes....
.

At one time, scholars perceived Posidonius's influence in almost every subsequent writer, whether warranted or not. Today, Posidonius seems to be recognized as having had an inquiring and wide-ranging mind, not entirely original, but with a breadth of view that connected, in accordance with his underlying Stoic philosophy, all things and their causes and all knowledge into an overarching, unified world view.

The crater Posidonius
Posidonius (crater)

Posidonius is a lunar impact crater that is located on the western edge of Mare Serenitatis, to the south of Lacus Somniorum. The crater Chacornac is attached to the southeast rim, and to the north is Daniell ....
 on the Moon
Moon

The Moon is Earth's only natural satellite and the List of natural satellites by diameter satellite in the Solar System. The average centre-to-centre distance from the Earth to the Moon is km, about thirty times the diameter of the Earth....
 is named after him.

See also

  • Twin Study
    Twin study

    Twin studies are one of a family of designs in behavior genetics which aid the study of individual differences by highlighting the role of environmental and genetics causes on behavior....
Freeman,Phillip,The Philosopher and the Druids: A Journey Among The Ancient Celts, Simon and Schuster,2006.
  • William B. Irvine, (2008), A Guide to the Good Life: The Ancient Art of Stoic Joy. Oxford University Press. ISBN 978-0-19-537461-2 — Discussion of his work and influence.


External links