Which body humor is associated with the concept of melancholy?

The association of black bile with melancholy originates from ancient medical theories, particularly the concept of the four humors, which was prominent in both Greek and later medieval medical thinking. According to this theory, the balance of four bodily fluids—blood, phlegm, yellow bile, and black bile—was thought to influence an individual's temperament and health.

Black bile, in particular, was believed to be linked with sadness, depression, and a generally melancholic disposition. Its excess was thought to lead to a state of melancholy, characterized by deep sadness or gloom. This connection is reflected in literature and psychological terminology, where "melancholy" has historically been used to describe a state of profound sadness and introspection, aligning closely with the properties attributed to black bile.

The other humors—blood, phlegm, and yellow bile—are associated with different temperamental states and health influences. Blood is linked with a sanguine temperament, characterized by cheerfulness and sociability; phlegm is associated with a phlegmatic temperament, which encompasses calmness and apathy; and yellow bile relates to a choleric temperament, characterized by irritability and anger. Thus, the specific association of black bile with melancholy makes it the correct choice in this