General Discussion

The imbalance of humors, or dyscrasia, was thought to be the direct cause of all diseases. Health was associated with a balance of humors, or eucrasia. The qualities of the humors, in turn, influenced the nature of the diseases they caused. Yellow bile caused warm diseases and phlegm caused cold diseases. In On the Temperaments, Galen further emphasized the importance of the qualities. An ideal temperament involved a proportionally balanced mixture of the four qualities. Galen identified four temperaments in which one of the qualities (warm, cold, moist, or dry) predominated, and four more in which a combination of two (warm and moist, warm and dry, cold and dry, or cold and moist) dominated. These last four, named for the humors with which they were associated—sanguine, choleric, melancholic and phlegmatic—eventually became better known than the others. While the term temperament came to refer just to psychological dispositions, Galen used it to refer to bodily dispositions, which determined a person's susceptibility to particular diseases, as well as behavioral and emotional inclinations.