Original: According to Galen, these elements were used by Hippocrates in describing the human body with an association with the four humours: yellow bile (fire), black bile (earth), blood (air), and phlegm (water).
Simplified: Galen said these elements were used by Hippocrates to describe the human body. The elements are linked to the four humours: phlegm (water), yellow bile (fire), black bile (earth), and blood (air).