This Professor told us some rather interesting stuff ..... 'bout the four humors ... it seems our body consists of four elemental fluids. They are: Yellow Bile (Fire) Black Bile (Earth) Phlegm (Water) Blood (Air) Each of the humors was associated with one of the four universal elements (Fire, Earth, Water & Air). An imbalance in the distribution of these fluids was thought to affect each individual's personality Too much blood, made one SANGUINE; these people are generally amorous , sturdy, confident, cheerful, sociable, carefree, lively. Too much black bile, MELANCHOLIC ; and these people are usually moody, anxious, sentimental, introspective, reserved Too much yellow bile, CHOLERIC ; and these folks are easily angered, agressive, short-tempered, ambitious, restless, impulsive & too much phlegm, PHLEGMATIC; they are calm, unemotional, cool, impassive, careful, reliable, even-tempered