This article is about the "four humors" in Greco-Roman medicine, a specific form of the more universal proto-medical concept of humorism. For George Balanchine's 1946 ballet, see The Four Temperaments (ballet). For the symphony by Carl Nielsen, see Symphony No. 2 (Nielsen).
Choleric, melancholic, sanguine, and phlegmatic temperaments
Four temperaments is a proto-psychological theory that suggests that there are four fundamental personality types, sanguine (pleasure-seeking and sociable), choleric (ambitious and leader-like), melancholic (analytical and quiet), and phlegmatic (relaxed and peaceful). Most formulations include the possibility of mixtures of the types.
The Greek physician Hippocrates (460–370 BC) incorporated the four temperaments into his medical theories as part of the ancient medical concept of humorism, that four bodily fluids affect human personality traits and behaviors. Later discoveries in biochemistry have led modern medicine science to reject the theory of the four temperaments, although some personality type systems of varying scientific acceptance continue to use four or more categories of a similar nature.