Homeopathy was invented by Samuel Hahnemann, 1755-1843. Hahnemann studied medicine, graduating from the University of Erlangen in 1779. 18th century medicine In Hahnemann's time, medicine was still largely based on a model that had first been described more than two thousand years earlier in Ancient Greece. According to this ancient theory — usually referred to as 'vitalism' — disease was the result of a disturbance of metaphysical vital forces caused by an imbalance in the four bodily 'humours' or liquids: phlegm, blood, gall and choler. When Hahnemann was studying medicine, doctors were prescribing remedies made from mercury and arsenic and inflicting barbaric treatments on patients in their attempts to 'restore the humoural balance' believed to be necessary for sound mental and physical health. These included purging, leeching and bloodletting — treatments that had been used for thousands of years because people believed they were effective. That some patients recovered in spite of