The Catalogus Codicum Astrologorum Graecorumshows the large amount of
astrology literature that had been produced in Byzantium, although most of the extant
manuscripts belong to the twelfth century. In this same century, despite the opposition
of the church, there was interest in astrology—sometimes even within the church
itself—although the stars were now considered to be signs rather than causes of events.
In the western world the study of the stars, called astronomy, was one of the
seven artes liberalescomprising the education curriculum of the time (along with
grammar, rhetoric, dialectic, arithmetic, geometry, and music). The fathers of the
Latin church condemned astrology as magic and as pagan. Augustine, referring to
astrology in De civitate Dei(The City of God), asserted that it was mere superstition.
The fundamental astrology text, the Tetrabiblos,was not yet known to the Latins, who
had only a few sources on astronomy (such as a chapter on astronomy in The Marriage
of Mercury and Phylologiaeby Martianus Capella, the Commentaryby Macrobius in the
fourth century, and the works of Isidore and Bede during the seventh century).
In the sixth century, astronomy was defined by Cassiodoro (490–583), secre-
tary at the court of Teodoricus, the Ostrogoth king of Italy, as the science that exam-
ines the heavenly bodies and their relation to one another and to Earth. It was not
until the early seventh century that an effort was made to distinguish between astron-
omy and astrology—in the Etymologiaeof Isidore, bishop of Seville. The definitions in
the Etymologiaeshow how in antiquity it was impossible to consider as independent
two arts considered as complementary as these. The study of the stars and the compu-
tus(the art of computing the calendar) were also part of monastic education, as a tool
for calendrical reference to the course of time through the year.
A reawakened interest in astrology in the Western world began under the influ-
ence of the Arabs, who had been settled in Spain and Sicily since the eighth century.
The Arabs were the heirs of the philosophy and culture of Hellenistic Greece—a her-
itage they blended with Syrian, Indian, and Persian cultures—and this knowledge began
to spread to the schools of northwestern Europe. Although in Islamic culture astrology
was generally opposed for many of the same reasons as in Christianity, scientific and
intellectual interest in the movements of the stars persisted in the work of such Muslim
astrologers as Masha’allah, al-Kindi, Abu ̄ Ma‘shar, and al-Battani. The works of these
scholars were eventually translated into Latin. Al-Kindi and Abu ̄ Ma‘shar (ninth centu-
ry) especially provided philosophical underpinnings for astrology, under the influence of
Aristotelianism, Neoplatonism, Neopythagoreanism, and Stoicism.
In the early 1100s Ptolemy’s Tetrabibloswas translated, possibly by Plato of
Tivoli, from an Arabic edition that also contained information on Persian and Indian
astrology. It became attractive for Western Latin intellectuals to study the astrological
system of the Arabs, with its new terminology and complexity, alongside Ptolemy’s
Tetrabiblosand Almagest.Also, the discovery of Aristotle’s Physics,among other works,
was instrumental in the following centuries in supporting the validity of astrology in
understanding natural science (medicine, alchemy, and meteorology). The intellectu-
al milieu in which this new literature was accepted—the only intellectual milieu of
the time before the first universities were founded in the thirteenth century—was that
created by the Church. In Europe, paganism had disappeared and the superstitious
THEASTROLOGYBOOK [315]
History of Western Astrology