Four Humors

The theory that human temperament and behavior are governed by bodily fluids and planetary influences was developed in the classical period and accepted and elaborated upon by medieval scientists and encyclopedists. The four fundamental, dominating fluids within the human body were identified as: Phlegm (causing a phlegmatic or sluggish temperament), Blood (causing a sanguine or optimistic temperament), Red Bile (or Choler , causing a   choleric, or excitable, temperament), and Black Bile (causing a melancholic or lazy temperament). The Four Humors were also linked with the *Four Elements, the planets, *zodiac signs, and specific *animals with shared characteristics . The systems are often illustrated in medieval works dealing with science, medicine, and astrology and also find pictorial form in human personifications of the various temperaments, accompanied by the appropriate animals and carrying attributes indicative of their natures (e.g., the choleric holds a sword, the melancholic has a crutch).