The man’s pointing finger serves as a warning
against the powerful forces of the stars.
Doctors often carried around special almanacs (or calendars) containing star charts, allowing them to check the positions of the stars before making a diagnosis. Many of these almanacs included pictures which helped to explain complicated ideas to patients. The picture above shows a 'zodiac man' from one of these almanacs.
Ancient studies of astrology were translated from Arabic to Latin in the 12th and 13th centuries and soon became a part of everyday medical practice in Europe. Doctors combined Galenic medicine (inherited from the Greek physiologist Galen - AD 129-216) with careful studies of the stars. By the end of the 1500s, physicians across Europe were required by law to calculate the position of the moon before carrying out complicated medical procedures, such as surgery or bleeding.