Four seasons, four elements, four directions... four humours. In ancient Greece it seemed clear that just as our world was built from four elements, our bodies must be regulated by four vital fluids. When these humours fell out of balance, disease and bad moods followed. For centuries doctors practiced medicine based on this idea: identify which fluid is winning and remove some of it until the patient stops complaining. It wasn’t until the 20th century that a discovery truly revolutionised medicine and finally laid this theory to rest. Cure your curiosity and listen to this week’s episode of Good in Theory.