The Marginalization of Astrology: Introduction
Astrology was an integral part of university teaching in the Middle Ages. The discipline of astronomia comprehended not only the calculation of planetary orbits, but also the casting of horoscopes, the calculation of houses and aspects, the character of the various planets, and the like. Although the astronomical and astrological parts were separate and had their own textbooks, both domains were taught in the same body of education. However, starting in the seventeenth century, universities gradually no longer considered the teaching of astrological techniques as their task. Astronomy developed further without any link to astrological pursuits. Something similar happened in the field of medicine. Medieval medicine and surgery had strong astrological ties, as is evident in the famous theory of 'critical days' of health and illness. The origin of a disease was often attributed, among other things, to the celestial constellation, and many cures had an astrological component as well. Most notably, bloodletting was performed in consideration of the astrological calendar. In the eighteenth century, however, leading physicians and surgeons generally no longer appealed to celestial causality. Their theories and practices barely referred to the power of the stars. What is true of medicine is so of many other fields as well. According to the traditional Aristotelian theory, generation and decay in the terrestrial world were caused by the influence of the heavens. Many physical and chemical