Weathering History on Instagram: "Humorism was an old medical belief that a person’s health, emotions, and personality were controlled by four bodily fluids called humors: blood, phlegm, yellow bile, and black bile. People in the 1600s thought that being healthy meant keeping these humors in balance and that illnesses or mood changes happened when they were out of balance. Each humor was linked to certain personality traits (for example, too much blood was thought to make someone cheerful, while