What are the 'four humors'? Hippocrates is often credited with developing the theory of the "four humors," or fluids. The philosophers Aristotle and Galen also contributed to the concept.

In this gallery we'll look at the four humors (which translate into four temperaments) and the lessons we can take from this proto-psychological theory. Click through the gallery to learn more.

Given these combinations, the humors could be matched onto the four seasons, the four elements, and—here's the mental health bit—four different emotional characteristics.

Ancient Greek doctors included Hippocrates, the “father of medicine.” How did the Greeks practice medicine, and how does this relate to health in our times? Find out more.

Mina Seçkin's The Four Humors is an engrossing exploration of national identity, the meaning of family and loss, and what happens when a family hides its central secret. Seçkin is a Turkish ...

Leading medical minds were once convinced that health and sickness resulted from the interplay of the four "humors": blood, phlegm, black bile and yellow bile, each associated with a certain ...

This week, on Halloween, I gave my second-year history students the entire history of psychiatry in 50 minutes. Well, it was actually 55 minutes—I went over, I admit. Starting in about 5000BC ...