Montpelier Physician

Medieval scientists came up with many theories to explain the origins of plague. Many relied on the theory of corrupted elements— earth, air, fire, and water; others saw the Black Death as an extreme example of the humors of the body—blood, phlegm, yellow bile, and black bile—being out of their normal equilibrium. In the following excerpt, written in 1349, an anonymous physician of the city of Montpelier, France, gives his opinion on the origins of the plague as an evil spirit that travels from the eyes of a sick person to a healthy victim.

This epidemic, according to some people, has the power to kill large numbers by air alone, simply by the breath or the conversation of the sick. They say that the air breathed out by the sick...