Astrology

Astrology, the effort to relate earthly occurrences to the stars and planets, is one of the oldest known intellectual endeavors. The oldest evidence for the Western tradition of astrology comes from Mesopotamia in the late third millennium B.C.E. Mesopotamian astronomical documents correlated celestial phenomena like eclipses with public events, including political changes and natural catastrophes. The first surviving "natal" horoscope, recounting the position of the planets at an individual's birth, is also Mesopotamian and dates from the late fifth century B.C.E. One Mesopotamian people, the Babylonians or Chaldeans, long remained famed for their astrological ability. Astrologers generally were called Chaldeans as early as the first century B.C.E. in Rome.

Greek interest in astrology began in the Hellenistic period, as Alexander the Great's (r. 336–323) conquests exposed Greek thinkers to Mesopotamian culture. The Greeks put astronomy in a cosmological framework, emphasizing the motions of the planets rather than static correlations. Hellenistic Alexandria was a center of astrology, and the Hermetic texts that originated there incorporated astrology into their magical and religious system. The Hellenistic period also saw the first evidence of Jews embracing astrology, a practice traditional Judaism condemned.

The Roman upper classes also initially condemned astrology, which they associated with popular divination and superstition. This position is reflected in Marcus Tullius Cicero's (106–43 B.C.E.) On Divination. Following the Roman conquest of the Hellenistic east in the first century B.C.E., Roman interest in astrology increased. The earliest evidence for Roman astrologers dates from this period. The Stoic school of philosophy, popular among the Roman elite, endorsed astrology along with other forms of divination. (The Epicureans, great rivals of the Stoics, condemned it.) Astrology became particularly prominent in the Roman Empire, as Augustus Caesar (63 B.C.E.–14 C.E.) employed it in his propaganda, subsequent emperors employed court astrologers, and rebels and aspirants to the imperial throne consulted astrologers to estimate their chances for success.

The imperial period saw the first surviving Latin astrological work, the Roman poet Manlius's Stoic-influenced Astronomica. Manlius had little astronomical or mathematical skill, however, and the most important astrological writer in the Roman Empire was the Greek astronomer Claudius Ptolemy (2nd century C.E.), author of the most influential ancient astrological book, Tetrabiblios. Ptolemy, more a codifier than an innovator in astrology, defended it as a science of the influence of the stars on the terrestial world based on conjecture rather than certainty. The early Christians attacked astrology, associating it with determinism and Gnosticism. St. Augustine of Hippo's (354–430) denunciation of astrology in The City of God was particularly influential in the Latin West. The Christian Roman Empire included astrology in its strong antidivination laws, which were however only sporadically enforced.