Following the discovery of Arabic texts, the Church absorbed astrology and
disapproved of it only when it seemed to imply fatalistic determinism (as in the case of
Cecco d’Ascoli), which contradicted man’s free will and God’s omnipotence. Also,
the writings of intellectuals in the fourteenth and fifteenth centuries, such as Nicole
d’Oresme, Peter d’Ailly, and Jean Gerson, show that astrology was still part of contem-
porary science, and few doubts about its validity appear.
In the early Renaissance, various cultural and historical factors contributed to
the development of interest in astrology. First, the technological improvement of print-
ing techniques favored the production of ephemerides, almanacs, charts and calendars,
and so on. In 1474, the first ephemeris, Ephemeris ad XXXII annos futuros,by
Regiomantanus (Johann Müller, 1436–1476), eminent mathematician and astronomer,
was printed in Nuremberg, and a second edition in Venice in 1484. In 1489, the Intro-
ductorium in astronomiaby Abu ̄ Ma‘shar was translated into Latin from Arabic.
Another important factor in the new interest in astrology was increased appre-
ciation of the rediscovered classical authors of antiquity, beginning with the first
humanists at the end of the fourteenth century. One reason for the new interest in the
ancients was the siege of the city of Constantinople by the Turks in 1453, which
forced Greek scholars to flee from the city (taking with them their literature) to Italy,
a country that had already shown a renewed interest in the classics of the ancient
world. Some Greek scholars were already settled in Italy before the siege of Constan-
tinople. Manuel Chrysoloras, whose nephew, Marsilio Ficino (1433–1499), was one of
the most important figures in the history of occultism during the Renaissance, went to
teach Greek in Florence in 1396. The Florentine court of Cosimo de’ Medici was also
one of the first cultural centers to offer refuge to the Greeks and, as a consequence, to
develop an interest in astrology.
At the Medici court, Ficino and Giordano Bruno (1548–1600) worked as the
translators of Plato’s writings (thus rediscovering Neoplatonism). Ficino also wrote
the Pimander,a hermetic work full of astrological elements. A physician as well as an
intellectual, Ficino also wrote De vita libri tres,a medical treatise on the health of the
intellectual; in the third part of the book, “De vita coelitus comparanda,” he describes
his vision of astrology and planetary influences on one’s health.
The intellectuals of the early fifteenth century could read the Picatrix,an Arab
compilation translated into Spanish (in 1256), which dealt largely with astrological
magic and influenced Ficino and his student Pico della Mirandola (1463–1494). The
application of astrology to medicine (iatromathematics) received attention from
Paracelsus (Bombast von Hohenheim, 1493–1541), who considered astrology a means
of understanding one’s innate physical disposition and allowing better control of one’s
life. Medical astrology was also the focus of the Amicus medicorum,written in 1431 by
Jean Ganivet and in use for the following two centuries throughout the Western world.
Although court astrologers continued to enjoy their position as consultants to
kings and princes, their way of doing astrology was the object of an ongoing intellec-
tual debate. The astrology of natal charts and forecasting the future, called judicial
astrology, was considered superstitious by the intellectuals of the period. This kind of
astrology was contrasted with iatromathematics, the study of the influence of the
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History of Western Astrology