Medieval Astrology

by Friar Thomas Bacon (David Moreno)
Orignally published in the January 2002, A.S. XXXVI issue of the Dragonflyre, a publication of the Barony of Vatavia.

One of the adjectives applied to the Middle Ages often is superstitious. Like all generalizations, the truth is more subtle. The usual implication of the charge is that those so accused are ignorant of how the world works and invents non-rational causes to the happenings around them. While the people of that time did not have the mechanistic view of the world current today, that does not mean that their explanations were non-rational given their concept of the world. Nor were all explanations were uncritically accepted. One the more controversial was astrology.

Astrology has its roots in Babylonian astronomy. The Babylonians were the first to systematically note the regularities of the sky. They were not the first to note them, but to organize them into a larger scheme of things. And this lead to the effort to correlate human affairs to these sky motions. While many details have change since then, the basic scheme has remained the same.

As excepted, Christianity was, and is, hostile to astrology, it did not unleash a major attack against it. Instead, like many other non-Christian religious elements, it co-opted it. The key was adapting the philosopher Plotinusís idea that while the stars could influence a personís physical being, they had no effect on his soul. Another dodge used was the idea that the stars were not the causes of events, but were signs for these events. Freed from this constraint on human will, early Christian writers proceed to use astrological imagery. The most prominent was identifying Christ as the sun. Also popular was identify the twelve signs of the Zodiac with the twelve apostles, with various themes of Christian theology.

With the fall of Rome and the subsequent loss of astronomical knowledge reduced the practice of astrology, but not the underlining concepts. Surviving in folklore were no only the ideas that things like comets and eclipses were adverse events, but that certain days were propitious starting projects, travel, or special occasions. Astrology began its comeback during the time of Charlemagne. Even then, astronomical practice was only up to supporting a rudimentary form. In the thirteenth century ancient astronomical tables, augmented by Islamic observations, became available again, allowing for more complex astrological calculations to be made. In an ironic twist of fate, it was the effort to correct the errors in these tables for astrological purposes that would lead to the astronomical revolution of Copernicus and Kepler.

Besides divination, the major use of astrology in the Middle Ages was in the practice of medicine. The concept behind this was the idea that man was a microcosm of the larger universe. Thus a manís health was reflection of the state of the universe. So part of the diagnosis involved understand the ill personís relationship with the world. And this could be done though astrology. As with most things medieval, the system got quite complex in practice, with each part of the body with its own Zodiacal signifier which governed when operations could take place.

In a lesser role, astrology had a part in alchemy. While alchemy is best known for the quest of making gold, to the true adept this was a secondary goal. The true goal was the production of the philosopherís stone, a material of transcendental quality. With the stone all things were possible. But the process of making the stone was as much a metaphysical journey as it was a series of chemical processes. Not only was astrology employed to determine when an operation was to occur, but with the actual steps involved larded with astrological images.

Astrology reached its height of influence in the late Renaissance. Astrologers could be found in most courts, and frequently consulted by those with means. Yet this influence was limited, rarely directing policy, affecting merely timing, most frequently of weddings. Its fall from grace came from the twin blows of the Enlightenment and the witch hunts of the seventeenth century. The first marked the change in the world view that underpinned astrology. The second, evidence of reduced acceptance of the mysterious.



Kieckhefer, Richard. Magic in the Middle Ages. Cambridge: Cambridge University Press, 1989.

McCluskey, Stephen C. Astronomies and Cultures in Early Medieval Europe. Cambridge: Cambridge University Press, 1998.

Rawcliffe, Carole. Medicine & Society in Later Medieval England. Stroud: Sutton Publishing Ltd., 1995.

Walker, Christopher, ed. Astronomy Before the Telescope. New York: St. Martins Press, 1996.


Copyright © 1997 - present His Lordship Friar Thomas Bacon (David Moreno). All rights reserved.

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