humours, theory of

Theory prevalent in the West in classical and medieval times that the human body was composed of four kinds of fluid: phlegm, blood, choler or yellow bile, and melancholy or black bile. Physical and mental characteristics were explained by different proportions of humours in individuals.

An excess of phlegm produced a ‘phlegmatic’, or calm, temperament; of blood a ‘sanguine’, or passionate, one; of yellow bile a ‘choleric’, or irascible, one; and of black bile a ‘melancholy’, or depressive, one. The Greek physician Galen connected the theory to that of the four elements (see elements, the four): the phlegmatic was associated with water, the sanguine with air, the choleric with fire, and the melancholic with earth. An imbalance of the humours could supposedly be treated by diet.