The Ancient Greek language includes the forms of Greek used in Ancient Greece and the ancient world from around the 9th century BCE to the 6th century CE. It is roughly divided into the Archaic period, Classical period, Hellenistic period, it is succeeded by medieval Greek. Koine is regarded as a separate historical stage of its own, although in its earliest form it resembled Attic Greek and in its latest form it approaches Medieval Greek. Prior to the Koine period, Greek of the classic and earlier periods included several regional dialects. Ancient Greek was the language of Homer and of fifth-century Athenian historians and philosophers, it has contributed many words to English vocabulary and has been a standard subject of study in educational institutions of the Western world since the Renaissance. This article contains information about the Epic and Classical periods of the language. Ancient Greek was a pluricentric language, divided into many dialects; the main dialect groups are Attic and Ionic, Aeolic and Doric, many of them with several subdivisions.
Some dialects are found in standardized literary forms used in literature, while others are attested only in inscriptions. There are several historical forms. Homeric Greek is a literary form of Archaic Greek used in the epic poems, the "Iliad" and "Odyssey", in poems by other authors. Homeric Greek had significant differences in grammar and pronunciation from Classical Attic and other Classical-era dialects; the origins, early form and development of the Hellenic language family are not well understood because of a lack of contemporaneous evidence. Several theories exist about what Hellenic dialect groups may have existed between the divergence of early Greek-like speech from the common Proto-Indo-European language and the Classical period, they differ in some of the detail. The only attested dialect from this period is Mycenaean Greek, but its relationship to the historical dialects and the historical circumstances of the times imply that the overall groups existed in some form. Scholars assume that major Ancient Greek period dialect groups developed not than 1120 BCE, at the time of the Dorian invasion—and that their first appearances as precise alphabetic writing began in the 8th century BCE.
The invasion would not be "Dorian" unless the invaders had some cultural relationship to the historical Dorians. The invasion is known to have displaced population to the Attic-Ionic regions, who regarded themselves as descendants of the population displaced by or contending with the Dorians; the Greeks of this period believed there were three major divisions of all Greek people—Dorians and Ionians, each with their own defining and distinctive dialects. Allowing for their oversight of Arcadian, an obscure mountain dialect, Cypriot, far from the center of Greek scholarship, this division of people and language is quite similar to the results of modern archaeological-linguistic investigation. One standard formulation for the dialects is: West vs. non-west Greek is the strongest marked and earliest division, with non-west in subsets of Ionic-Attic and Aeolic vs. Arcadocypriot, or Aeolic and Arcado-Cypriot vs. Ionic-Attic. Non-west is called East Greek. Arcadocypriot descended more from the Mycenaean Greek of the Bronze Age.
Boeotian had come under a strong Northwest Greek influence, can in some respects be considered a transitional dialect. Thessalian had come under Northwest Greek influence, though to a lesser degree. Pamphylian Greek, spoken in a small area on the southwestern coast of Anatolia and little preserved in inscriptions, may be either a fifth major dialect group, or it is Mycenaean Greek overlaid by Doric, with a non-Greek native influence. Most of the dialect sub-groups listed above had further subdivisions equivalent to a city-state and its surrounding territory, or to an island. Doric notably had several intermediate divisions as well, into Island Doric, Southern Peloponnesus Doric, Northern Peloponnesus Doric; the Lesbian dialect was Aeolic Greek. All the groups were represented by colonies beyond Greece proper as well, these colonies developed local characteristics under the influence of settlers or neighbors speaking different Greek dialects; the dialects outside the Ionic group are known from inscriptions, notable exceptions being: fragments of the works of the poet Sappho from the island of Lesbos, in Aeolian, the poems of the Boeotian poet Pindar and other lyric poets in Doric.
After the conquests of Alexander the Great in the late 4th century BCE, a new international dialect known as Koine or Common Greek developed based on Attic Greek, but with influence from other dialects. This dialect replaced most of the older dialects, although Doric dialect has survived in the Tsakonian language, spoken in the region of modern Sparta. Doric has passed down its aorist terminations into most verbs of Demotic Greek. By about the 6th century CE, the Koine had metamorphosized into Medieval Greek. Ancient Macedonian was an Indo-European language at least related to Greek, but its exact relationship is unclear because of insufficient data: a dialect of Greek; the Macedonian dialect (or l
Syria was an early Roman province, annexed to the Roman Republic in 64 BC by Pompey in the Third Mithridatic War, following the defeat of Armenian King Tigranes the Great. Following the partition of the Herodian Kingdom into tetrarchies in 6 AD, it was absorbed into Roman provinces, with Roman Syria annexing Iturea and Trachonitis. Syria was an early Roman province, annexed to the Roman Republic in 64 BC by Pompey in the Third Mithridatic War, following the defeat of Armenian King Tigranes the Great. During the early empire, the Roman army in Syria accounted for three legions with auxiliaries, they defended the border with Parthia. Following the partition of the Herodian Kingdom into tetrarchies in 6 AD, it was absorbed into Roman provinces, with Roman Syria annexing Iturea and Trachonitis around 34 AD. Syrian province forces were directly engaged in the Great Jewish Revolt of 66–70 AD. In 66 AD, Cestius Gallus, the legate of Syria, brought the Syrian army, based on XII Fulminata, reinforced by auxiliary troops, to restore order in Judaea and quell the revolt.
The legion, was ambushed and destroyed by Jewish rebels at the Battle of Beth Horon, a result that shocked the Roman leadership. The future emperor Vespasian was put in charge of subduing the Jewish revolt. In the summer of 69, with the Syrian units supporting him, launched his bid to become Roman emperor, he defeated his rival Vitellius and ruled as emperor for ten years when he was succeeded by his son Titus. Based on an inscription recovered from Dor in 1948, Gargilius Antiquus was known to have been the governor of a province in the eastern part of the Empire Syria, between his consulate and governing Asia. In November 2016, an inscription in Greek was recovered off the coast of Dor by Haifa University underwater archaeologists, which attests that Antiquus was governor of the province of Judea between 120 and 130 prior to the Bar Kokhba revolt. Syria Palæstina was established by the merger of Roman Syria and Roman Judea, following the defeat of the Bar Kokhba Revolt in 135; the Syria-based legion took part in the quelling of the revolt in 132–136, in the aftermath, the emperor Hadrian added the depopulated province of Judea to the province of Syria thus forming Syria-Palaestina.
The governor of Syria retained the civil administration of the whole large province undiminished, held for long alone in all Asia a command of the first rank. It was only in the course of the second century that a diminution of his prerogatives occurred, when Hadrian took one of the four legions from the governor of Syria and handed it over to the governor of Palestine, it was Severus who at length withdrew the first place in the Roman military hierarchy from the Syrian governor. After having subdued the province amidst resistance from the capital Antioch in particular, he ordained its partition into a northern and a southern half, gave to the governor of the former, called Coele-Syria, two legions, to the governor of the latter, the province of Syro-Phoenicia, one legion; the emperor Septimius Severus divided up Roman Syria in the fashion it would remain until the rule of the Tetrarchs. Under his reign it was divided into three parts, Coele Syria in the north with Antioch as its provincial capital, Syria Phoenice with Tyre as the provincial capital and in the south Syria Palestina with Caesarea Maritima as the provincial capital.
From the 2nd century, the Roman Senate included several notable Syrians, including Claudius Pompeianus and Avidius Cassius. Syria was of crucial strategic importance during the Crisis of the Third Century. In 244 AD, Rome was ruled by a native Syrian from Philippopolis in the province of Arabia Petraea; the emperor was Marcus Iulius Philippus, more known as Philip the Arab. Philip became the 33rd emperor of Rome upon its millennial celebration. Roman Syria was invaded in 252/253 after a Roman field army was destroyed in the battle of Barbalissos by the King of Persia Shapur I which left the Euphrates river unguarded and the region was pillaged by the Persians. In 259/260 a similar event happened when Shapur I again defeated a Roman field army and captured the Roman emperor, alive at the battle of Edessa. Again Roman Syria suffered as cities were captured and pillaged. From 268 to 273, Syria was part of the breakaway Palmyrene Empire. Following the reforms of Diocletian, Syria Coele became part of the Diocese of Oriens.
Sometime between 330 and 350, the province of Euphratensis was created out of the territory of Syria Coele along the western bank of the Euphrates and the former realm of Commagene, with Hierapolis as its capital. After c. 415 Syria Coele was further subdivided into Syria I, with the capital remaining at Antioch, Syria II or Syria Salutaris, with capital at Apamea on the Orontes. In 528, Justinian I carved out the small coastal province Theodorias out of territory from both provinces; the region remained one of the most important provinces of the Byzantine Empire. It was occupied by the Sassanids between 609 and 628 recovered by the emperor Heraclius, but lost again to the advancing Muslims after the battle of Yarmouk and the fall of Antioch; the city of Antioch was recovered by Nikephorus Phocas in 963 AD, along with other parts of the country, at that time under the Hamdanids, although still under the official suzerainty of the Abbasid caliphs and claimed by the Fatimid caliphs. After emperor John Kurkuas's failed to recover Syria up to Jerusalem a Muslim "reconquest" of Syria followed in the late 970s undertaken by the Fatimid caliphate which resulted in the o
Music theory is the study of the practices and possibilities of music. The Oxford Companion to Music describes three interrelated uses of the term "music theory": The first is what is otherwise called'rudiments' taught as the elements of notation, of key signatures, of time signatures, of rhythmic notation, so on; the second is the study of writings about music from ancient times onwards. The third is an area of current musicological study that seeks to define processes and general principles in music — a sphere of research that can be distinguished from analysis in that it takes as its starting-point not the individual work or performance but the fundamental materials from which it is built. Music theory is concerned with describing how musicians and composers make music, including tuning systems and composition methods among other topics; because of the ever-expanding conception of what constitutes music, a more inclusive definition could be that music theory is the consideration of any sonic phenomena, including silence, as they relate to music.
This is not an absolute guideline. However, this medieval discipline became the basis for tuning systems in centuries, it is included in modern scholarship on the history of music theory. Music theory as a practical discipline encompasses the methods and concepts composers and other musicians use in creating music; the development and transmission of music theory in this sense may be found in oral and written music-making traditions, musical instruments, other artifacts. For example, ancient instruments from Mesopotamia and prehistoric sites around the world reveal details about the music they produced and something of the musical theory that might have been used by their makers. In ancient and living cultures around the world, the deep and long roots of music theory are visible in instruments, oral traditions, current music making. Many cultures, at least as far back as ancient Mesopotamia and ancient China, have considered music theory in more formal ways such as written treatises and music notation.
Practical and scholarly traditions overlap, as many practical treatises about music place themselves within a tradition of other treatises, which are cited just as scholarly writing cites earlier research. In modern academia, music theory is a subfield of musicology, the wider study of musical cultures and history. Etymologically, music theory is an act of contemplation of music, from the Greek θεωρία, a looking at, contemplation, theory a sight, a spectacle; as such, it is concerned with abstract musical aspects such as tuning and tonal systems, scales and dissonance, rhythmic relationships, but there is a body of theory concerning practical aspects, such as the creation or the performance of music, ornamentation and electronic sound production. A person who researches, teaches, or writes articles about music theory is a music theorist. University study to the M. A. or Ph. D level, is required to teach as a tenure-track music theorist in Canadian university. Methods of analysis include mathematics, graphic analysis, analysis enabled by Western music notation.
Comparative, descriptive and other methods are used. Music theory textbooks in the United States of America include elements of musical acoustics, considerations of musical notation, techniques of tonal composition, among other topics. Preserved prehistoric instruments and depictions of performance in artworks can give clues to the structure of pitch systems in prehistoric cultures. See for instance Paleolithic flutes, Gǔdí, Anasazi flute. Several surviving Sumerian and Akkadian clay tablets include musical information of a theoretical nature lists of intervals and tunings; the scholar Sam Mirelman reports that the earliest of these texts dates from before 1500 BCE, a millennium earlier than surviving evidence from any other culture of comparable musical thought. Further, "All the Mesopotamian texts are united by the use of a terminology for music that, according to the approximate dating of the texts, was in use for over 1,000 years." Much of Chinese music history and theory remains unclear.
The earliest texts about Chinese music theory are inscribed on the stone and bronze bells excavated in 1978 from the tomb of Marquis Yi of the Zeng state. They include more than 2800 words describing practices of music pitches of the time; the bells produce two intertwined pentatonic scales three tones apart with additional pitches completing the chromatic scale. Chinese theory starts from numbers, the main musical numbers being twelve and eight. Twelve refers to the number of pitches; the Lüshi chunqiu from about 239 BCE recalls the legend of Ling Lun. On order of the Yellow Emperor, Ling Lun collected twelve bamboo lengths with thick and nodes. Blowing on one of these like a pipe, he found its sound agreeable and named it huangzhong, the "Yellow Bell." He heard phoenixes singing. The male and female phoenix each sang six tones. Ling Lun cut his bamboo pipes to match the pitches of the phoenixes, producing twelve pitch pipes in two sets: six from the male phoenix and six from the female: these were called the lülü or the shierlü.
The lülü formed the ritual scale to which
Porphyry of Tyre was a Neoplatonic philosopher, born in Tyre, in the Roman Empire. He published the Enneads, the only collection of the work of his teacher Plotinus, his commentary on Euclid's Elements was used as a source by Pappus of Alexandria. He wrote many works himself on a wide variety of topics, his Isagoge, or Introduction, is an introduction to logic and philosophy, in the Latin and Arabic translations it was the standard textbook on logic throughout the Middle Ages. In addition, through several of his works, most notably Philosophy from Oracles and Against the Christians, banned by emperor Constantine the Great, he was involved in a controversy with a number of early Christians. Porphyry was born in Tyre, his parents named him Malchus but his teacher in Athens, Cassius Longinus, gave him the name Porphyrius a reference to his Phoenician heritage, or a punning allusion to his name and the color of royal robes. Under Longinus he studied rhetoric. In 262 he went to Rome, attracted by the reputation of Plotinus, for six years devoted himself to the practice of Neoplatonism, during which time he modified his diet.
At one point he became suicidal. On the advice of Plotinus he went to live in Sicily for five years to recover his mental health. On returning to Rome, he lectured on philosophy and completed an edition of the writings of Plotinus together with a biography of his teacher. Iamblichus is mentioned in ancient Neoplatonic writings as his pupil, but this most means only that he was the dominant figure in the next generation of philosophers; the two men differed publicly on the issue of theurgy. In his years, he married Marcella, a widow with seven children and an enthusiastic student of philosophy. Little more is known of his life, the date of his death is uncertain. Porphyry is best known for his contributions to philosophy. Apart from writing the Aids to the Study of the Intelligibles, a basic summary of Neoplatonism, he is appreciated for his Introduction to Categories, a short work considered to be a commentary on Aristotle's Categories, hence the title. According to Barnes, the correct title is Introduction, the book is an introduction not to the Categories in particular, but to logic in general, comprising as it does the theories of predication and proof.
The Introduction describes how qualities attributed to things may be classified, famously breaking down the philosophical concept of substance into the five components genus, difference, accident. As Porphyry's most influential contribution to philosophy, the Introduction to Categories incorporated Aristotle's logic into Neoplatonism, in particular the doctrine of the categories of being interpreted in terms of entities. Boethius' Isagoge, a Latin translation of Porphyry's "Introduction", became a standard medieval textbook in European schools and universities, which set the stage for medieval philosophical-theological developments of logic and the problem of universals. In medieval textbooks, the all-important Arbor porphyriana illustrates his logical classification of substance. To this day, taxonomy benefits in classifying living organisms; the Introduction was translated into Arabic by Abd-Allāh Ibn al-Muqaffaʿ from a Syriac version. With the Arabicized name Isāghūjī it long remained the standard introductory logic text in the Muslim world and influenced the study of theology, philosophy and jurisprudence.
Besides the adaptations and epitomes of this work, many independent works on logic by Muslim philosophers have been entitled Isāghūjī. Porphyry's discussion of accident sparked a long-running debate on the application of accident and essence. Porphyry is known as an opponent of Christianity and defender of Paganism. There is debate as to whether it was written in his youth or closer in time to the persecutions of Christians under Diocletian and Galerius. Whether or not Porphyry was the pagan philosopher opponent in Lactantius' Divine Institutes, written at the time of the persecutions, has long been discussed; the fragments of the Philosophy from Oracles are only quoted by Christians Eusebius, Theodoret and John Philoponus. The fragments contain oracles identifying proper sacrificial procedure, the nature of astrological fate, other topics relevant for Greek and Roman religion in the third century. Whether this work contradicts his treatise defending vegetarianism, which warned the philosopher to avoid animal sacrifice, is disputed among scholars.
During his retirement in Sicily, Porphyry wrote Against the Christians which consisted of fifteen books. Some thirty Christian apologists, such as Methodius, Apollinaris, Jerome, etc. responded to his challenge. In fact, everything known about Porphyry's arguments is found in these refutations because Theodosius II ordered every copy burned in A. D. 435 and again in 448. Porphyry became one of the most able pagan adversaries of Christianity of his day, his aim was not to di
Aristoxenus of Tarentum was a Greek Peripatetic philosopher, a pupil of Aristotle. Most of his writings, which dealt with philosophy and music, have been lost, but one musical treatise, Elements of Harmony, survives incomplete, as well as some fragments concerning rhythm and meter; the Elements is the chief source of our knowledge of ancient Greek music. Aristoxenus was born at Tarentum, was the son of a learned musician named Spintharus, he learned music from his father, having been instructed by Lamprus of Erythrae and Xenophilus the Pythagorean, he became a pupil of Aristotle, whom he appears to have rivaled in the variety of his studies. According to the Suda, he heaped insults on Aristotle after his death, because Aristotle had designated Theophrastus as the next head of the Peripatetic school, a position which Aristoxenus himself had coveted having achieved great distinction as a pupil of Aristotle; this story is, contradicted by Aristocles, who asserts that he never mentioned Aristotle but with the greatest respect.
Nothing is known of his life after the time of Aristotle's departure, apart from a comment in Elementa Harmonica concerning his works. His writings, said to have consisted of four hundred and fifty-three books, dealt with philosophy and music. Although his final years were in the Peripatetic School, he hoped to succeed Aristotle on his death, Aristonexus was influenced by Pythagoreanism, was only a follower of Aristotle in so far as Aristotle was a follower of Plato and Pythagoras. Thus, as Sophie Gibson tells us, “the various philosophical influences” on Aristoxenus included growing up in the profoundly Pythagorean city of Taras, home of the two Pythagoreans Archytas and Philolaus, his father's musical background, which he inculcated into his son. Gibson tells us that, after the influence of his father: The second important influence on Aristoxenos’ development was Pythagoreanism. Born in Tarentum, the city in which both Archytas and Philolaos had lived, it can be seen that the extended period of time that Aristoxenus spent in a Pythagorean environment made an indelible impact on the subject matter of his writings.
Such titles as "Pythagorou bios", "Peri Pythaorou kai ton guorimon autou" and "Peri tou Pythagorikou biou" indicate Aristoxenus’ interest in the society. Furthermore, his works on education show evidence of Pythagorean influence in their tendency towards conservatism. Most speculation on the structure of music had its origin in a Pythagorean environment, its focus was on the numerical relationship between notes and, at its furthest stretch, developed into a comparison between musical and cosmological structures. However, Aristoxenus disagreed with earlier Pythagorean musical theory in several respects, building on their work with ideas of his own; the only work of his that has come down to us is the three books of the Elements of Harmony, an incomplete musical treatise. Aristoxenus' theory had an empirical tendency. Vitruvius in his De architectura paraphrases the writings of Aristoxenus on music, his ideas were responded to and developed by some theorists such as Archestratus, his place in the methodological debate between rationalists and empiricists was commented upon by such writers as Ptolemais of Cyrene.
The Pythagorean theory that the soul is a'harmony' of the four elements composing the body, therefore mortal, was ascribed to Aristoxenus and Dicaearchus. This theory is comparable to the one offered by Simmias in Plato's Phaedo. In his Elements of Harmony, Aristoxenus attempted a systematic exposition of music; the first book contains an explanation of the genera of Greek music, of their species. In the second book Aristoxenus divides music into seven parts, which he takes to be: the genera, sounds, tones or modes and melopoeia; the remainder of the work is taken up with a discussion of the many parts of music according to the order which he had himself prescribed. While it is held among modern scholars that Aristoxenus rejected the opinion of the Pythagoreans that arithmetic rules were the ultimate judge of intervals and that in every system there must be found a mathematical coincidence before such a system can be said to be harmonic, it must be noted that Aristoxenus made extensive use of arithmetic terminology, notably to define varieties of semitones, dieses in his descriptions of the various genera.
In his second book he asserted that "by the hearing we judge of the magnitude of an interval, by the understanding we consider its many powers." And further he wrote, "that the nature of melody is best discovered by the perception of sense, is retained by memory. However, this should not be construed as meaning that he postulated a simplistic system of harmony resembling that of modern twelve tone theory
Aristotle was a philosopher during the Classical period in Ancient Greece, the founder of the Lyceum and the Peripatetic school of philosophy and Aristotelian tradition. Along with his teacher Plato, he is considered the "Father of Western Philosophy", his writings cover many subjects – including physics, zoology, logic, aesthetics, theatre, rhetoric, linguistics, economics and government. Aristotle provided a complex synthesis of the various philosophies existing prior to him, it was above all from his teachings that the West inherited its intellectual lexicon, as well as problems and methods of inquiry; as a result, his philosophy has exerted a unique influence on every form of knowledge in the West and it continues to be a subject of contemporary philosophical discussion. Little is known about his life. Aristotle was born in the city of Stagira in Northern Greece, his father, died when Aristotle was a child, he was brought up by a guardian. At seventeen or eighteen years of age, he joined Plato's Academy in Athens and remained there until the age of thirty-seven.
Shortly after Plato died, Aristotle left Athens and, at the request of Philip II of Macedon, tutored Alexander the Great beginning in 343 BC. He established a library in the Lyceum which helped him to produce many of his hundreds of books on papyrus scrolls. Though Aristotle wrote many elegant treatises and dialogues for publication, only around a third of his original output has survived, none of it intended for publication; the fact that Aristotle was a pupil of Plato contributed to his former views of Platonism, following Plato's death, Aristotle developed an increased interest in natural sciences and adopted the position of immanent realism. Aristotle's views on physical science profoundly shaped medieval scholarship, their influence extended from Late Antiquity and the Early Middle Ages into the Renaissance, were not replaced systematically until the Enlightenment and theories such as classical mechanics. Some of Aristotle's zoological observations found in his biology, such as on the hectocotyl arm of the octopus, were disbelieved until the 19th century.
His works contain the earliest known formal study of logic, studied by medieval scholars such as Peter Abelard and John Buridan. Aristotle's influence on logic continued well into the 19th century He influenced Islamic thought during the Middle Ages, as well as Christian theology the Neoplatonism of the Early Church and the scholastic tradition of the Catholic Church. Aristotle was revered among medieval Muslim scholars as "The First Teacher" and among medieval Christians like Thomas Aquinas as "The Philosopher", his ethics, though always influential, gained renewed interest with the modern advent of virtue ethics, such as in the thinking of Alasdair MacIntyre and Philippa Foot. In general, the details of Aristotle's life are not well-established; the biographies written in ancient times are speculative and historians only agree on a few salient points. Aristotle, whose name means "the best purpose" in Ancient Greek, was born in 384 BC in Stagira, about 55 km east of modern-day Thessaloniki.
His father Nicomachus was the personal physician to King Amyntas of Macedon. Both of Aristotle's parents died when he was about thirteen, Proxenus of Atarneus became his guardian. Although little information about Aristotle's childhood has survived, he spent some time within the Macedonian palace, making his first connections with the Macedonian monarchy. At the age of seventeen or eighteen, Aristotle moved to Athens to continue his education at Plato's Academy, he remained there for nearly twenty years before leaving Athens in 348/47 BC. The traditional story about his departure records that he was disappointed with the Academy's direction after control passed to Plato's nephew Speusippus, although it is possible that he feared the anti-Macedonian sentiments in Athens at that time and left before Plato died. Aristotle accompanied Xenocrates to the court of his friend Hermias of Atarneus in Asia Minor. After the death of Hermias, Aristotle travelled with his pupil Theophrastus to the island of Lesbos, where together they researched the botany and zoology of the island and its sheltered lagoon.
While in Lesbos, Aristotle married Hermias's adoptive daughter or niece. She bore him a daughter, whom they named Pythias. In 343 BC, Aristotle was invited by Philip II of Macedon to become the tutor to his son Alexander. Aristotle was appointed as the head of the royal academy of Macedon. During Aristotle's time in the Macedonian court, he gave lessons not only to Alexander, but to two other future kings: Ptolemy and Cassander. Aristotle encouraged Alexander toward eastern conquest and Aristotle's own attitude towards Persia was unabashedly ethnocentric. In one famous example, he counsels Alexander to be "a leader to the Greeks and a despot to the barbarians, to look after the former as after friends and relatives, to deal with the latter as with beasts or plants". By 335 BC, Aristotle had returned to Athens. Aristotle conducted courses at the school for the next twelve years. While in Athens, his wife Pythias died and Aristotle became involved with Herpyllis of Stagira, who bore him a son whom he named after his father, Nicomachus.
According to the Suda, he had an erômenos, Palaephatus of Abydus. This period in Athens, between 335 and 323 BC, is when Aristotle is believed to have composed many of his works, he wrote many dialogues. Those works that have survived are in treatise form and were not
Astronomy is a natural science that studies celestial objects and phenomena. It applies mathematics and chemistry in an effort to explain the origin of those objects and phenomena and their evolution. Objects of interest include planets, stars, nebulae and comets. More all phenomena that originate outside Earth's atmosphere are within the purview of astronomy. A related but distinct subject is physical cosmology, the study of the Universe as a whole. Astronomy is one of the oldest of the natural sciences; the early civilizations in recorded history, such as the Babylonians, Indians, Nubians, Chinese and many ancient indigenous peoples of the Americas, performed methodical observations of the night sky. Astronomy has included disciplines as diverse as astrometry, celestial navigation, observational astronomy, the making of calendars, but professional astronomy is now considered to be synonymous with astrophysics. Professional astronomy is split into theoretical branches. Observational astronomy is focused on acquiring data from observations of astronomical objects, analyzed using basic principles of physics.
Theoretical astronomy is oriented toward the development of computer or analytical models to describe astronomical objects and phenomena. The two fields complement each other, with theoretical astronomy seeking to explain observational results and observations being used to confirm theoretical results. Astronomy is one of the few sciences in which amateurs still play an active role in the discovery and observation of transient events. Amateur astronomers have made and contributed to many important astronomical discoveries, such as finding new comets. Astronomy means "law of the stars". Astronomy should not be confused with astrology, the belief system which claims that human affairs are correlated with the positions of celestial objects. Although the two fields share a common origin, they are now distinct. Both of the terms "astronomy" and "astrophysics" may be used to refer to the same subject. Based on strict dictionary definitions, "astronomy" refers to "the study of objects and matter outside the Earth's atmosphere and of their physical and chemical properties," while "astrophysics" refers to the branch of astronomy dealing with "the behavior, physical properties, dynamic processes of celestial objects and phenomena."
In some cases, as in the introduction of the introductory textbook The Physical Universe by Frank Shu, "astronomy" may be used to describe the qualitative study of the subject, whereas "astrophysics" is used to describe the physics-oriented version of the subject. However, since most modern astronomical research deals with subjects related to physics, modern astronomy could be called astrophysics; some fields, such as astrometry, are purely astronomy rather than astrophysics. Various departments in which scientists carry out research on this subject may use "astronomy" and "astrophysics" depending on whether the department is affiliated with a physics department, many professional astronomers have physics rather than astronomy degrees; some titles of the leading scientific journals in this field include The Astronomical Journal, The Astrophysical Journal, Astronomy and Astrophysics. In early historic times, astronomy only consisted of the observation and predictions of the motions of objects visible to the naked eye.
In some locations, early cultures assembled massive artifacts that had some astronomical purpose. In addition to their ceremonial uses, these observatories could be employed to determine the seasons, an important factor in knowing when to plant crops and in understanding the length of the year. Before tools such as the telescope were invented, early study of the stars was conducted using the naked eye; as civilizations developed, most notably in Mesopotamia, Persia, China and Central America, astronomical observatories were assembled and ideas on the nature of the Universe began to develop. Most early astronomy consisted of mapping the positions of the stars and planets, a science now referred to as astrometry. From these observations, early ideas about the motions of the planets were formed, the nature of the Sun and the Earth in the Universe were explored philosophically; the Earth was believed to be the center of the Universe with the Sun, the Moon and the stars rotating around it. This is known as the geocentric model of the Ptolemaic system, named after Ptolemy.
A important early development was the beginning of mathematical and scientific astronomy, which began among the Babylonians, who laid the foundations for the astronomical traditions that developed in many other civilizations. The Babylonians discovered. Following the Babylonians, significant advances in astronomy were made in ancient Greece and the Hellenistic world. Greek astronomy is characterized from the start by seeking a rational, physical explanation for celestial phenomena. In the 3rd century BC, Aristarchus of Samos estimated the size and distance of the Moon and Sun, he proposed a model of the Solar System where the Earth and planets rotated around the Sun, now called the heliocentric model. In the 2nd century BC, Hipparchus discovered precession, calculated the size and distance of the Moon and inven