"the 18th century German inventor of homeopathy, Samuel Hahnemann, believed in 'vitalism,' a spiritual essence that goes beyond physics or chemistry. This is by no means unusual; most people believe in spiritual or religious cures even today. 'Medicine is most powerful,' Hahnemann wrote, 'when it communicates nothing material' [...] Hahnemann typically used a dilution of 30C [...] this would exceed the dilution limit of the entire Earth, which is to say it's a meaningless result [...] Oscillococcinum [...] also marketed as a homeopathic cold remedy [...is] at a ridiculous dilution of 200C. That would exceed the dilution limit of the entire visible universe and is thus totally meaningless. The average consumer is totally unaware that he's shelling out 10 bucks for a teaspoon of sugar."
Note: hear, hear.