When the Moon is in the Seventh House: Astrology, Astronomy and Medicine

Dr. Jeremy Wasser

Beginning in antiquity and continuing into the early modern period a critical component of medical practice centered on observations of the planets and the starry constellations. People in the ancient and medieval world believed that the sun and planets revolved around the earth (the geocentric model). There was no real distinction between astrology and astronomy until the development of the heliocentric model of the solar system (that the planets revolved around the sun). Before (and even after) the revolutionary work of Copernicus, Kepler, and Tycho Brahe, the border between astrology and astronomy was fluid and a belief in one did not preclude expertise and a belief in the other.

“Medical Mathematics” was a course taught in medieval European medical schools. But this was not what we moderns would think of as quantitative medicine, for example statistics and epidemiology. Rather it constituted a training in astrology and astronomy, how to read the heavens for a specific patient at a specific time and use that arcane knowledge to provide a diagnosis, a prognosis and to develop a therapy.

In this course, we will explore the history of the application of astrology and astronomical science to medical practice from antiquity through the early modern period. We will trace the development of astronomical knowledge of the sun, the visible planets, the moon, and the stars and explore the theories that developed about the potential influence of these stellar bodies on the lives and fates of human beings. Our focus will be on the theories that developed around the concept (to reverse the famous quote from Shakespeare’s Julius Ceasar) that the fault (our destiny) does lie in our stars and not in ourselves, at least in terms of our health and physical well-being. Where did these ideas come from? How did the ideas evolve over time and how were they applied in a myriad of ways to the art and science of medicine?