The Temperaments Explained
The modern day understanding of the temperaments is that of a two-dimensional system, one axis compromising that of strong/weak emotions (characterized as "stable"/"unstable") and the other that of short-/long- lasting emotions (characterized as "extroverted"/"introverted").
Combining these two axes, we get the following four types:
Choleric — Quickly Roused, Active, Impulsive, Aggressive, Touchy, Excitable
Melancholic — Anxious, Worried, Suspicious, Serious, Thoughtful, Sover, Rigid, Moody
Sanguine — Playful, Sociable, Carefree, Hopeful, Leadership, Talkative, Outgoing
Phlegmatic — Calm, Reasonable, Thoughtful, Controlled, Persistent, Peaceful, Passive
Throughout history there have been many attempts to explain why people are different. One of the first systems developed was Astrology, which looked outside of man to explain the differences. There were twelve “signs” symbolized by earth, air, fire and water. Hippocrates, however, looked inside of man to explain the differences. He believed that behavior was determined by the presence of an excessive amount of one of four fluids or humors; yellow bile (Chlor); red bile or blood (Sangis); white bile (Phlegm); black bile (Melan). These four humors were thought to be related to the four elements of earth, air, fire and water. Hippocrates, and other early Greeks, thought that an excess of one of the four humors produced a particular temperament and behavior.
The word “temperament” comes from the Latin word temperamentum and means right blending. The Greeks thought that a person’s “temperament” was therefore made up of a blending of these four fluids.
Hippocrates and the early Greeks were accurate in their observations of behavior but were incorrect about the origin of these tendencies (they are not created by the excess of a fluid). Today we would say that they originate from some genic predisposition, although we cannot be certain