The physician Galen
(130-199 AD) elaborated a model of health and disease as a structure of elements, qualities, humors, organs, and temperaments. Health was understood in this perspective to be a condition of harmony or balance (eucrasia
) among these basic components that make up both nature in general and the individual body. Disease was interpreted as the disproportion (dyscrasia
) of bodily fluids or four humours
: phlegm, blood, and yellow and black bile.