Long before the theories of Isabel Myers, Katharine Briggs, or Carl Jung, there was the idea that humanity was divided into four archetypal groups or temperaments. Whether it has been used to explain how an individual can achieve happiness (Aristotle) or the very nature of our physical being (Hippocrates), this idea holds a special place in antiquity. In the last quarter century, the greatest proponent of this idea was David Keirsey, a psychologist, professor, and author (more here).
Here are descriptions of the 4 Temperaments (also found under “The 4 Temperaments” at the top of the site):
