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Although the study of astrology has been pursued in many cultures and continues to have an important role in the Far East, this article deals only with Babylonian astrology and its subsequent development in the Greco-Roman world and in Europe. It is important to note that astrology, in many aspects at least, was recognized as a sciencenot as a pseudo-scienceuntil the 18th century.

Babylonian Astrology. The chief source for information about Babylonian astrology is the library of King Assurbanipal (668626 b.c.) at Nineveh, from which many thousands of astrological documents and fragments, embodying a simple type of astrology that did not distinguish celestial from terrestrial phenomena, have been recovered. Babylonian horoscopes were applied to the royal family and the land; the earliest known prediction for a private person dates from 263 b.c. The following example is typical: "If an eclipse of the moon occurs on 14 Sivan and the fourth [east] wind is blowing, enmity will prevail; there will be deaths."

It is not surprising that astrology arose in Mesopotamia, with its extremely clear atmosphere and a religion that identified various gods with particular heavenly bodies. Babylonian astrology rests ultimately on a single large work of unknown date written in about 70 large tablets, fragmentarily preserved in several recensions. This system, unlike that of the Greeks later, made the Moon more important than the Sun (probably because of its easy observability and conspicuous phases) and arranged the planets in the so-called Babylonian order: Moon, Sun, Jupiter, Venus, Saturn, Mercury, Mars. More than 200 constellations were distinguished, as well as 12 signs of the zodiac, and attention was paid also to comets, meteors, winds, storms, earthquakes, clouds, thunder, and lightning. Although the documents are in Old Babylonian and Assyrian, traces of Sumerian usage suggest that some of this material is earlier than 2000 b.c.

In Classical Greece. Though the early Greeks practiced various forms of divination, they had no astrology. Minoan art shows little concern with the heavens, and few early Greek myths deal with the stars. Even an author as late as Aristophanes (Peace 406413; 421 b.c.) can refer to the Sun and Moon as barbarian gods. Zeus, despite the etymology of his name, was far more to the Greeks than a sky-god; and this broader conception accords with the fact that the major Greek gods, unlike the Semitic, were not closely bound to nature. The stars were observed for purposes of navigation, but there is hardly a trace of astral religion. Thales of Miletus (6th-century b.c.) and his successors derived much, directly or indirectly, from Babylonian sources (e.g., the rough prediction of solar eclipses, celestial equator, ecliptic, planets,

constellations, the 12-hour day), but they used these data to construct a scientific cosmology. Typical of classical Greek rationalism is the story of Pericles (Plutarch, Pericles 35), who calmed a frightened sailor by holding up his cloak to show how an eclipse occurs. Among the classical Greeks prophecy based on such phenomena as eclipses and lightning was on the same footing as prophecy from the flight of birds, the entrails of sacrificial animals, and dreams. There were no special astrological techniques.

Greek reason, however, provided a potentially hospitable environment for the introduction of astrology: if the world is governed by unchanging (scientific) laws, then fatalism becomes easy. The early Pythagoreans illustrate the possibilities. They discovered the oldest known scientific laws by experiments with the strings of musical instruments, but they also developed numerical and geometrical symbolisms involving astral elements, such as the harmony of the spheres.

Plato and even Aristotle (who was no mystic) believed the stars to be divine, no doubt under Oriental influence. The planets play an important role in the myth of Er, son of Armenius (an Oriental name), at the end of the Republic, and Plato emphasizes the relationship between souls and stars in Timaeus (41D). The appendix to the Laws by Plato's nephew and successor, Philip of Opus, is full of astral lore. Such developments prepared the way for astrology, though so distinguished an astronomer as Eudoxus of Cnidus (c. 350 b.c.) was opposed to it.

Rise of Astrology in the Hellenistic Age. Between Alexander and Augustus the Greek world was altered by world-shaking political, economic, and cultural upheavals. Reason (logos ) gave way to esoteric knowledge (gnosis ). Imperturbability (ataraxia ) before the buffetings of fortune became the great desideratum, and chance was deified (see fate and fatalism). Carneades (214128 b.c.) and Panaetius (c. 185109 b.c.) might oppose astrology, but Posidonius (c. 13550 b.c.) and Hipparchus of Nicaea (c. 190c. 126 b.c.), the greatest Greek astronomer, both accepted its validity.

It was in Hellenistic Egypt, where all races and cultures mingled, that Greek astrology finally developed. There is no evidence of astrology in Egypt under the old Kingdom, but Babylonian lore reached there under the Ptolemies and was combined with the exact data of Greek astronomy to produce the strange two-headed monster of astrology, partly religious and mystical and partly scientific. There can be no doubt about the importance of Greek astronomy in this development, for the standard order of the planets was the so-called Greek, which is based on the observed periods of revolution: Moon, Mercury, Venus, Sun, Mars, Jupiter, Saturn. The Sun was most important, not the Moon as in Babylonian astrology. Some Egyptian star lore also entered the system: for example, the decans, a series of 36 constellations, each ruled a ten-day week. The earliest authoritative handbook now known, called Nechepso-Petosiris (c. 170150 b.c.) after the names of its supposed authors, remained the astrological bible until the publication of Ptolemy's Tetrabiblos.

Dominance of Astrology in the Greco-Roman World. Astrology swept the Greco-Roman world, reaching all races, nations, and types of men: rulers, scholars (such as Varro), philosophers (see neopythagoreanism), and also the well-to-do, both aristocrats and nouveaux riches (such as Trimalchio in Petronius's Cena Trimalchionis 39, 77). It invaded the sciences of medicine, botany, chemistry (via alchemy), and mineralogy. It had a central place also in the mystery religions, especially that of Mithras, whose votaries invoked the planet ruling the day of the week. In the end, only the skeptics and Epicureans held out against astrology.

At first it was available only to the rich; the necessary computations were complicated and difficult, and consequently astrologers were often called mathematici. But the Julian calendar reform of 46 b.c., introduced later in outlying parts of the empire, changed this. The Sun now entered a new sign of the zodiac, usually on the 25th of the month, the Moon was easily observable, and the planets were assigned each to a day of the week (first evidence is found in Tibullus, 1.3.18). With the new calendar the poorest persons, even slaves, could afford astrology, and its use became almost universal. The popularity of talismans and amulets shows that astrology was often combined with belief in magic, while the educated resorted to it because it contributed to apathy by removing the unexpected. Stoicism was its natural home. The final, complete victory of astrology is well illustrated by the emperor Aurelian's introduction of the worship of Sol invictus into the state cult after his victory over Palmyra in a.d. 273.

Astrology's success is hard for the Western mind to comprehend, but it doubtless came about because astrology offered a causal explanation, based on the most advanced science, of everything that occurs. Since people of antiquity often thought "in myths," no one attacked the mythological foundation of astrology. It could, and sometimes did, lead to atheism, as in the case of the emperor Tiberius; but to most men it was a cosmology that was also a religion, and a universal religion in contrast with belief in the Greek and Roman gods, who were essentially local.

Astrology and Christianity. Christianity is fundamentally opposed to astrology; yet the earliest Christian documents contain references to it, partly in opposition (Gal 4.911; Rom 8.38; Col 1.16; 2.8, 20), but partly because astrology permeated the entire culture. The Church, by calling Christ "the sun of justice" (a phrase derived from Mal 3.20), substituted Him for Sol; and in the 4th century it deliberately put His Nativity on December 25, the birthday of the Sun, when "lux crescit." Christ was now "the light of the world" in a symbolic sense, but His day was still called dies solis (Sunday) in the West, as contrasted with Kyriake (the Lord's Day) in the East. The Gospels speak of the eclipse at Christ's death and of the wonderful star seen by the Magi, a phenomenon that Christian defenders of astrology always cited. Astrology must have continued or even begun to revive among Christians, for Tertullian found it necessary to state that God tolerated it only until Christ's birth. Lactantius and St. Augustine believed that demons were at work in the stars and in astrology, but that their influence could be overcome through God's grace. It should be observed that astrology is logically compatible with a belief in predestination.

Astrology among the Byzantines and in Islam. The Church Fathers were not completely successful in rooting astrology out, since it pervaded all ancient culture, and it revived during the Byzantine renaissance of the 9th century along with Greek astronomy, which was rediscovered partly in original Greek documents and partly in Arabic translations. The Byzantine emperor Manuel Comnenus (a.d. 114380) relied on astrology and defended it on the basis of natural science, the Gospels, and the Fathers. Greek translations of Arabic and Persian astrological treatises became common, though some leading Byzantine astronomers and Churchmen condemned the art. The revived Greek doctrines spread from Byzantium to the West long before the fall of Constantinople.

Astrology flourished under Arabic influence, for Islam is essentially fatalistic, and it spread to the West from Arabic sources as well as from the Greek East. While Avicenna and ibn-Khaldun condemned it, such influential thinkers as al-Kindi and Averroës supported it. As late as 1909 the sultan Abdul-Hamid II still had a court astrologer. Christians came in contact with Arabs not only during the Crusades but also in Spain and Sicily, so that scholastic philosophy was brought face to face with the problem of astrology. The scholastic philosopher, Michael Scotus (d. c. 1235) was court astrologer to Frederick II of Sicily, whose son-in-law Ezzelino also kept astrologers about him, including some Saracens. Roger Bacon also recognized astrology as a science. Many Italian cities, dynasties, and prelates resorted to astrologers; and since medieval culture was international, astrology spread rapidly throughout Europe as early as the 13th century.

Astrology in the Renaissance and Later. Astrology was used by Pope Julius II to set the day of his coronation and by Paul III to determine the proper hour for every Consistory. Leo X founded a chair of astrology at the Sapienza, for by that time no respectable university could ignore the subject. Down to the 18th century many literary works, buildings, and works of plastic art were unintelligible without a knowledge of astrological doctrines.

Astrology pervaded European culture just as it had the culture of the Roman Empire, and, though official Church doctrine opposed it, no one attacked the whole manner of thinking that lay behind it. Even St. Thomas Aquinas had attributed physique, sex, and general character to the stars, and was followed by Dante ("Purg." 17.73). "Inclinant astra, non necessitant" (the stars influence, they do not compel) was the most that Christian thinkers would allow. The humanists, inspired by later antiquity, only strengthened the movement, and the Reformation made no difference. Melanchthon, for example, lectured on astrology at Wittenberg and published a standard Latin translation of Ptolemy's Tetrabiblos. The leading astronomers, including Kepler, Tycho Brahe, and (later) Newton, were usually astrologers also.

The invention of the telescope damaged astrology seriously. The seven Pleiades, of which most people can see but six, were discovered to include scores. Two more planets, Uranus and Neptune, were presently discovered, as well as hundreds of planetoids between Mars and Jupiter, and thousands of stars whose very existence destroyed the apparent primacy of the traditional constellations. Astrology's neat system, which had never been really neat or systematic, broke down. As a pseudo-science astrology survives only among the uneducated and the credulous, while the influence of the heavenly bodies upon Earth and man has become the subject of various strictly scientific studies without occult implication.

See Also: astral religion.

Bibliography: m. vereno and j. c. pilz, Lexikon für Theologie und Kirche, ed. j. hofer and k. rahner, 10 v. (2d, new ed. Freiburg 195765) suppl., Das Zweite Vatikanische Konzil: Dokumente und Kommentare, ed. h. s. brechter et al., pt. 1 (1966) 1:964967. j. h. crehan, h. f. davis et al., A Catholic Dictionary of Theology (London 1962) 1:179182, with bibliog. f. von oefele et al., Encyclopedia of Religion and Ethics, ed. j. hastings, 13 v. (Edinburgh 190827) 12:48103, a comprehensive world coverage. f. j. boll, Sternglaube und Sterndeutung, ed. w. gundel (4th ed. Leipzig 1931).

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