The Four Humours were a set of four bodily fluids believed to determine a person's health and personality in Medieval Medicine. These were blood, phlegm, black bile, and yellow bile. It was thought that a balance among these humours was essential for good health, and imbalance caused illness.

Source A: Medieval Explanation of the Four Humours

'Health depended on the balance of these four fluids; excess or deficiency led to sickness.' Provenance: Medieval medical textbook, 14th century.

The theory of the Four Humours became widely accepted because it provided a simple explanation for health and illness that fit with religious and philosophical beliefs of the time.

Source B: Explanation of the Spread of Humour Theory

'The Four Humours aligned with religious ideas about balance and moral conduct, making it easy to integrate into daily life.' Provenance: Medieval religious scholar, 15th century.

Relying on the Four Humours influenced how people diagnosed and treated illnesses. Treatments aimed to restore balance, often through methods like bloodletting and purging.

Source C: Medieval Treatment Based on Humours

'To restore balance, physicians often used bloodletting, leeches, or purgatives, which could sometimes harm the patient.' Provenance: Medical manual, 15th century.

The belief in the Four Humours shaped medical practices for centuries, influencing how people understood health and illness. Its reliance on imbalance caused both treatments and misconceptions that persisted until scientific advances changed medicine.

Source D: Reflection on Medieval Medicine

'The Four Humours theory was a significant step in the history of medicine, but its limitations show the importance of scientific progress.' Provenance: Modern historian, 21st century.