The document discusses the four temperaments theory of personality - Phlegmatic, Choleric, Melancholic, and Sanguine. It traces the history of temperament theory from Hippocrates to modern day. Each temperament is associated with a different element - Phlegmatic with Water, Choleric with Fire, Melancholic with Earth, and Sanguine with Air. Each type is described in terms of strengths, weaknesses, and special roles. For example, Phlegmatics are described as peace-loving, indecisive but good teachers, Cholerics are activists and good leaders but quick to anger.