The Four Humours of Hippocrates.

 

The four humors of Hippocratic medicine were black bile (gr. melan chole), yellow bile (gr. chole), phlegm (gr. phlegma), and blood (lat. sanguisEssentially, this theory held that the human body was filled with four basic substances, called four humors, which are in balance when a person is healthy. All diseases and disabilities resulted from an excess or deficit of one of these four humors. These deficits could be caused by vapors that were inhaled or absorbed by the body. When a patient was suffering from a surplus or imbalance of one fluid, then his or her personality and physical health would be affected. This theory was closely related to the theory of the four elements: earth, fire, water and air; earth predominantly present in the black bile, fire in the yellow bile, water in the phlegm, and all four elements present in the blood.
The four humors, their corresponding elements, seasons, sites of formation, and resulting temperaments alongside their modern equivalents are

Humour	Season	Element	Organ	Qualities	Ancient name	Modern	Ancient characteristics
Blood	spring	air	liver	warm & moist	sanguine	artisan	courageous, hopeful, amorous
Yellow bile	summer	fire	gall bladder	warm & dry	choleric	idealist	easily angered, bad tempered
Black bile	autumn	earth	spleen	cold & dry	melancholic	guardian	Despondent. sleepless, irritable
Phlegm	winter	water	brain/lungs	cold & moist	phlegmatic	rational	calm, unemotional